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1. Experimental and theoretical confirmation of an orthorhombic phase transition in niobium at high pressure and temperature

Author

Errandonea, Daniel, Burakovsky, Leonid, Preston, Dean L., MacLeod, Simon G., Santamaria-Perez, David, Chen, Shaoping, Cynn, Hyunchae, Simak, Sergey I., McMahon, Malcolm I., Proctor, John E., and Mezouar, Mohamed

Subjects
Condensed Matter - Materials Science
Abstract

Compared to other body-centered cubic (bcc) transition metals Nb has been the subject of fewer compression studies and there are still aspects of its phase diagram which are unclear. Here, we report a combined theoretical and experimental study of Nb under high pressure and temperature. We present the results of static laser-heated diamond anvil cell experiments up to 120 GPa using synchrotron-based fast x-ray diffraction combined with ab initio quantum molecular dynamics simulations. The melting curve of Nb is determined, and evidence for a solid-solid phase transformation in Nb with increasing temperature is found. The high-temperature phase of Nb is orthorhombic Pnma. The bcc-Pnma transition is clearly seen in the experimental data on the Nb principal Hugoniot. The bcc-Pnma coexistence observed in our experiments is explained. Agreement between the measured and calculated melting curves is very good except at 40-60 GPa where three experimental points lie below the theoretical melting curve by 250 K (or 7%); a possible explanation is given., Comment: 33 pages, 10 figures

Published
2024
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2. Experimental and theoretical study of SbPO4 under compression

Author

Pereira, André Luis de Jesus, Santamaría-Pérez, David, Vilaplana, Rosário, Errandonea, Daniel, Popescu, Catalin, da Silva, Estelina Lora, Sans, Juan Angel, Rodríguez-Carvajal, Juan, Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Mujica, Andres, Radescu, Silvana Elena, Beltrán, Armando, de la Roza, Alberto Otero, Nalin, Marcelo, Mollar, Miguel, and Manjón, Francisco Javier

Subjects
Condensed Matter - Materials Science
Abstract

SbPO4 is a complex monoclinic layered material characterized by a strong activity of the non-bonding lone electron pair (LEP) of Sb. The strong cation LEP leads to the formation of layers piled up along the a-axis and linked by weak Sb-O electrostatic interactions. In fact, Sb is 4-fold coordination with O similar to what occurs with the P-O coordination, despite the large difference of ionic radii and electronegativity between both elements. Here we report a joint experimental and theoretical study of the structural and vibrational properties of SbPO4 at high pressure. We show that SbPO4 is not only one of the most compressible phosphates but also one of the most compressible compounds of the ABO4 family. Moreover, it has a considerable anisotropic compression behavior with the largest compression occurring along a direction close to a-axis and governed by the compression of the LEP and the weak inter-layer Sb-O bonds. The strong compression along the a-axis leads to a subtle modification of the monoclinic crystal structure above 3 GPa leading from a 2D to a 3D material. Moreover, the onset of a reversible pressure-induced phase transition is observed above 9 GPa, which is completed above 20 GPa. We propose that the high-pressure phase is a triclinic distortion of the original monoclinic phase. The understanding of the compression mechanism of SbPO4 can aid in understanding the importance of the ion intercalation and catalytic properties of this layered compound., Comment: Main text - 43 pages Supplementary Information - 13 pages

Published
2021
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3. Pressure impact on the stability and distortion of the crystal structure of CeScO3

Author

Errandonea, Daniel, Santamaria-Perez, David, Martinez-Garcia, Domingo, Gomis, Oscar, Shukla, Rakesh, Achary, S. Nagabhusan, Tyagi, Avesh K., and Popescu, Catalin

Subjects
Condensed Matter - Materials Science, Condensed Matter - Other Condensed Matter, Physics - Chemical Physics
Abstract

The effects of high pressure on the crystal structure of orthorhombic (Pnma) perovskite type cerium scandate have been studied in situ under high pressure by means of synchrotron x-ray powder diffraction, using a diamond anvil cell. We have found that the perovskite type crystal structure remains stable up to 40 GPa, the highest pressure reached in the experiments. The evolution of unit-cell parameters with pressure has indicated an anisotropic compression. The room-temperature pressure-volume equation of state is obtained from the experiments. From the evolution of microscopic structural parameters like bond distances and coordination polyhedra of cerium and scandium, the macroscopic behavior of CeScO3 under compression has been explained and reasoned for its large pressure stability. The reported results are discussed in comparison with high-pressure results from other perovskites., Comment: 39 pages, 1 table, 9 figures

Published
2017
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5. Helium ordered trapping in arsenolite under compression: Synthesis of He2As4O6

Author

Sans, Juan Angel, Manjón, Francisco Javier, Popescu, Catalin, Cuenca-Gotor, Vanesa Paula, Gomis, Oscar, Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Pellicer-Porres, Julio, Pereira, Andre Luis de Jesus, Santamaría-Pérez, David, and Segura, Alfredo

Subjects
Condensed Matter - Materials Science
Abstract

The compression of arsenolite (cubic As2O3) has been studied from a joint experimental and theoretical point of view. Experimental X-ray diffraction and Raman scattering measurements of this molecular solid at high pressures with different pressure-transmitting media have been interpreted with the help of ab initio calculations. Our results confirm arsenolite as one of the softest minerals in absence of hydrogen bonding and provide evidence for helium trapping above 3 GPa between adamantane-type As4O6 cages, thus leading to a new compound with stoichiometry He2As4O6. Helium trapping alters all properties of arsenolite. In particular, pressure-induced amorphization, which occurs in pure arsenolite above 15 GPa, is impeded when He is trapped between the As4O6 cages; thus resulting in a mechanical stability of He2As4O6 beyond 30 GPa. Our work paves the way for the modification of the properties of other molecular solids by compression depending on their ability to trap relatively small atomic or molecular species and form new compounds. Furthermore, our work suggests that compression of molecular solids with noble gases as helium could result in unexpected results compared to other pressure-transmitting media., Comment: 15 pages, 4 figures

Published
2015
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6. Polymorphism and Phase Stability of Hydrated Magnesium Carbonate Nesquehonite MgCO3·3H2O: Negative Axial Compressibility and Thermal Expansion in a Cementitious Material

Author

Santamaría-Pérez, David, primary, Chuliá-Jordán, Raquel, additional, Gonzalez-Platas, Javier, additional, Otero-de-la-Roza, Alberto, additional, Ruiz-Fuertes, Javier, additional, Pellicer-Porres, Julio, additional, Oliva, Robert, additional, and Popescu, Catalin, additional

Published
2024
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7. Exploring the Chemical Reactivity between Carbon Dioxide and Three Transition Metals (Au, Pt, and Re) at High-Pressure, High-Temperature Conditions

Author

Santamaría-Pérez, David, McGuire, Chris, Makhluf, Adam, Kavner, Abby, Chuliá-Jordán, Raquel, Pellicer-Porres, Julio, Martinez-García, Domingo, Doran, Andrew, Kunz, Martin, Rodríguez-Hernández, Plácida, and Muñoz, Alfonso

Subjects
Chemical Sciences, Physical Chemistry, Inorganic Chemistry, Physical Chemistry (incl. Structural), Other Chemical Sciences, Inorganic & Nuclear Chemistry, Inorganic chemistry, Macromolecular and materials chemistry
Abstract

The role of carbon dioxide, CO2, as oxidizing agent at high pressures and temperatures is evaluated by studying its chemical reactivity with three transition metals: Au, Pt, and Re. We report systematic X-ray diffraction measurements up to 48 GPa and 2400 K using synchrotron radiation and laser-heating diamond-anvil cells. No evidence of reaction was found in Au and Pt samples in this pressure-temperature range. In the Re + CO2 system, however, a strongly-driven redox reaction occurs at P > 8 GPa and T > 1500 K, and orthorhombic β-ReO2 is formed. This rhenium oxide phase is stable at least up to 48 GPa and 2400 K and was recovered at ambient conditions. Raman spectroscopy data confirm graphite as a reaction product. Ab-initio total-energy structural and compressibility data of the β-ReO2 phase shows an excellent agreement with experiments, altogether accurately confirming CO2 reduction P-T conditions in the presence of rhenium metal and the β-ReO2 equation of state.

Published
2016

8. Pbca-type In2O3: the lost pressure-induced post-corundum phase

Author

García-Domene, Braulio, Sans, Juan A., Gomis, Óscar, Manjón, Francisco J., Ortiz, Henry M., Errandonea, Daniel, Santamaría-Pérez, David, Martínez-García, Domingo, Vilaplana, Rosario, Pereira, André L. J., Morales-García, Ángel, Rodríguez-Hernández, Plácida, Muñoz, Alfonso, Popescu, Catalin, and Segura, Alfredo

Subjects
Condensed Matter - Materials Science
Abstract

Contradictory results of high-pressure studies in cubic bixbyite-type indium oxide (c-In2O3) at room temperature (RT) have motivated us to perform high-pressure powder x-ray diffraction and Raman scattering measurements in this material. On increasing pressure c-In2O3 undergoes a transition to the Rh2O3-II structure. On decreasing pressure Rh2O3-II-type In2O3 undergoes a transition to a previously unknown phase which is isostructural to Rh2O3-III. On further decrease of pressure, another phase transition to corundum-type In2O3, which is metastable at room conditions, is observed. Recompression of metastable corundum-type In2O3 shows that the Rh2O3-III phase is the post-corundum phase. Our results are supported by theoretical ab initio calculations which show that the Rh2O3-III phase could be present in other sesquioxides, thus leading to a revision of the pressure-temperature phase diagrams of sesquioxides., Comment: 14 pages, 7 figures, 2 tables

Published
2013

9. New high-pressure phase of HfTiO4 and ZrTiO4 ceramics

Author

Errandonea, Daniel, Santamaria-Perez, David, Bondarenko, Tatiana, and Khyzhun, Oleg

Subjects
Condensed Matter - Materials Science, Condensed Matter - Other Condensed Matter
Abstract

We studied the high-pressure effects on the crystalline structure of monoclinic HfTiO4 and ZrTiO4. We found that the compressibility of these ceramics is highly non-isotropic, being the b-axis the most compressible one. In addition, the a-axis is found to have a small and negative compressibility. At 2.7 GPa (10.7 GPa) we discovered the onset of an structural phase transition in HfTiO4 (ZrTiO4), coexisting the low- and high-pressure phases in a broad pressure range. The new high-pressure phase has a monoclinic structure which involves an increase in the Ti-O coordination and a collapse of the cell volume. The equation of state for the low-pressure phase is also determined., Comment: 16 pages, 5 figures, 26 references, Article in Press

Published
2010
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10. Size-Dependent High-Pressure Behavior of Pure and Eu 3+ -Doped Y 2 O 3 Nanoparticles: Insights from Experimental and Theoretical Investigations.

Author

Pereira, André Luis de Jesus, Sans, Juan Ángel, Gomis, Óscar, Santamaría-Pérez, David, Ray, Sudeshna, Godoy Jr., Armstrong, da Silva-Sobrinho, Argemiro Soares, Rodríguez-Hernández, Plácida, Muñoz, Alfonso, Popescu, Catalin, and Manjón, Francisco Javier

Subjects
NANOPARTICLES, PHASE transitions, RAMAN scattering, PHOTOLUMINESCENCE measurement, YTTRIUM oxides, AMORPHIZATION
Abstract

We report a joint high-pressure experimental and theoretical study of the structural, vibrational, and photoluminescent properties of pure and Eu3+-doped cubic Y2O3 nanoparticles with two very different average particle sizes. We compare the results of synchrotron X-ray diffraction, Raman scattering, and photoluminescence measurements in nanoparticles with ab initio density-functional simulations in bulk material with the aim to understand the influence of the average particle size on the properties of pure and doped Y2O3 nanoparticles under compression. We observe that the high-pressure phase behavior of Y2O3 nanoparticles depends on the average particle size, but in a different way to that previously reported. Nanoparticles with an average particle size of ~37 nm show the same pressure-induced phase transition sequence on upstroke and downstroke as the bulk sample; however, nanoparticles with an average particle size of ~6 nm undergo an irreversible pressure-induced amorphization above 16 GPa that is completed above 24 GPa. On downstroke, 6 nm nanoparticles likely consist of an amorphous phase. [ABSTRACT FROM AUTHOR]

Published
2024
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13. Compounds at High Pressures

Author

Santamaria-Perez, David, Ruiz-Fuertes, Javier, Hull, Robert, Series editor, Jagadish, Chennupati, Series editor, Osgood, Richard M., Series editor, Parisi, Jürgen, Series editor, Wang, Zhiming M., Series editor, Manjon, Francisco Javier, editor, Tiginyanu, Ion, editor, and Ursaki, Veaceslav, editor

Published
2014
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17. Crystal structure of HgGa2Se4 under compression

Author

Gomis, Oscar, Vilaplana, Rosario, Manjón, Francisco Javier, Santamaría-Pérez, David, Errandonea, Daniel, Pérez-González, Eduardo, López-Solano, Javier, Rodríguez-Hernández, Plácida, Muñoz, Alfonso, Tiginyanu, Ion Mihail, and Ursaki, Veaceslav Vladimir

Published
2013
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19. Role of rare earth sites and vacancies in the anomalous compression of modulated scheelite tungstates RE2 ( WO4)3

Author

Sabalisck, Nanci Prado, primary, Gil-de-Cos, Gerardo, additional, González-Silgo, Cristina, additional, Guzmán-Afonso, Candelaria, additional, Lavín, Víctor, additional, López-Solano, Javier, additional, Martín-Mateos, Isabel Teresa, additional, Mestres, Lourdes, additional, Mujica, Andrés, additional, Santamaría-Pérez, David, additional, Torres, Manuel Eulalio, additional, and Vendrell, Xavier, additional

Published
2021
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22. Experimental and Theoretical Study of SbPO4 under Compression

Author

Pereira, André Luis de Jesus, primary, Santamaría-Pérez, David, additional, Vilaplana, Rosário, additional, Errandonea, Daniel, additional, Popescu, Catalin, additional, da Silva, Estelina Lora, additional, Sans, Juan Angel, additional, Rodríguez-Carvajal, Juan, additional, Muñoz, Alfonso, additional, Rodríguez-Hernández, Plácida, additional, Mujica, Andres, additional, Radescu, Silvana Elena, additional, Beltrán, Armando, additional, Otero-de-la-Roza, Alberto, additional, Nalin, Marcelo, additional, Mollar, Miguel, additional, and Manjón, Francisco Javier, additional

Published
2019
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24. Experimental and Theoretical Study of Bi2O2Se Under Compression

Author

Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Czech Science Foundation, Agencia Estatal de Investigación, Ministerio de Economía y Competitividad, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, Pereira, A.L.J., Santamaría Pérez, David, Ruiz Fuertes, Javier, Manjón, Francisco-Javier, Cuenca Gotor, Vanesa Paula, Vilaplana Cerda, Rosario Isabel, Gomis, O., Popescu, Catalin, Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Segura, Alfredo, Gracia, L., Beltran, A., Ruleova, P., Drasar, C., Sans-Tresserras, Juan Ángel, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Czech Science Foundation, Agencia Estatal de Investigación, Ministerio de Economía y Competitividad, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, Pereira, A.L.J., Santamaría Pérez, David, Ruiz Fuertes, Javier, Manjón, Francisco-Javier, Cuenca Gotor, Vanesa Paula, Vilaplana Cerda, Rosario Isabel, Gomis, O., Popescu, Catalin, Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Segura, Alfredo, Gracia, L., Beltran, A., Ruleova, P., Drasar, C., and Sans-Tresserras, Juan Ángel

Abstract

[EN] We report a joint experimental and theoretical study of the structural, vibrational, elastic, optical, and electronic properties of the layered high-mobility semiconductor Bi2O2Se at high pressure. A good agreement between experiments and ab initio calculations is observed for the equation of state, the pressure coefficients of the Raman-active modes and the bandgap of the material. In particular, a detailed description of the vibrational properties is provided. Unlike other Sillen-type compounds which undergo a tetragonal to collapsed tetragonal pressure-induced phase transition at relatively low pressures, Bi2O2Se shows a remarkable structural stability up to 30 GPa; however, our results indicate that this compound exhibits considerable electronic changes around 4 GPa, likely related to the progressive shortening and hardening of the long and weak Bi-Se bonds linking the Bi2O2 and Se atomic layers. Variations of the structural, vibrational, and electronic properties induced by these electronic changes are discussed.

Published
2018

25. High-Pressure High-Temperature Stability and Thermal Equation of State of Zircon-Type Erbium Vanadate

Author

Ruiz-Fuertes, Javier, primary, Martínez-García, Domingo, additional, Marqueño, Tomás, additional, Errandonea, Daniel, additional, MacLeod, Simon G., additional, Bernert, Thomas, additional, Haussühl, Eiken, additional, Santamaría-Pérez, David, additional, Ibáñez, Jordi, additional, Mallavarapu, Anitha, additional, Achary, S. Nagabhusan, additional, Popescu, Catalin, additional, and Bettinelli, Marco, additional

Published
2018
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27. Metastable structural transformations and pressure-induced amorphization in natural (Mg,Fe)2SiO4 olivine under static compression: A Raman spectroscopic study

Author

Santamaría Pérez, David, Thomson, Andrew, Segura, Alfredo, Pellicer Torres, Julio, Manjón, Francisco-Javier, Cora, Furio, McColl, Kit, Wilson, Mark, Dobson, David, and McMillan, Paul

Subjects
Metastable phase transition, High-density silicate glass, FISICA APLICADA, Raman spectroscopy, TEORIA DE LA SEÑAL Y COMUNICACIONES, Defect formation, San Carlos olivine, Amorphization
Abstract

[EN] Raman spectroscopic data were obtained for (Mg,Fe)(2)SiO4 samples during compression to 57 GPa. Single crystals of San Carlos olivine compressed hydrostatically above 41 GPa showed appearance of a new "defect" peak in the 820-840 cm(-1) region associated with SiOSi linkages appearing between adjacent SiO44- tetrahedra to result in five- or sixfold-coordinated silicate species. Appearance of this feature is accompanied by a broad amorphous background. The changes occur at lower pressure than metastable crystalline transitions of end-member Mg2SiO4 forsterite (Fo-I) into Fo-II and Fo-III phases described recently. We complemented our experimental study using density functional theory (DFT) calculations and anisotropic ion molecular dynamics (AIMD) simulations to study the Raman spectra and vibrational density of states (VDOS) of metastably compressed Mg2SiO4 olivine, Fo-II and Fo-III, and quenched melts at high and low pressures. By 54 GPa all sharp crystalline peaks disappeared from observed Raman spectra indicating complete pressure-induced amorphization (PIA). The amorphous (Mg,Fe)(2)SiO4 spectrum contains Si-O stretching bands at lower wavenumber than expected for SiO44- indicating high coordination of the silicate units. The amorphous spectrum persisted on decompression to ambient conditions but with evidence for reappearance of tetrahedrally coordinated units. Non hydrostatic compression of polycrystalline olivine samples showed similar appearance of the defect feature and broad amorphous features between 43-44 GPa. Both increased in intensity as the sample was left at pressure overnight but they disappeared during decompression below 17 GPa with recovery of the starting olivine Raman signature. A hydrated San Carlos olivine sample containing 75-150 ppm OH was also studied. Significant broadening of the SiO44- stretching peaks was observed above 43 GPa but without immediate appearance of the defect or broad amorphous features. However, both of these characteristics emerged after leaving the sample at 47 GPa overnight followed by complete amorphization that occurred upon subsequent pressurization to 54 GPa. During decompression the high-density amorphous spectrum was retained to 3 GPa but on final pressure release a spectrum similar to thermally quenched low-pressure olivine glass containing isolated SiO44- groups was obtained. Leaving this sample overnight resulted in recrystallization of olivine. Our experimental data provide new insights into the metastable structural transformations and relaxation behavior of olivine samples including material recovered from meteorites and laboratory shock experiments., Our work was supported by the U.K. NERC via Grant NE/K002902/1 and Spanish MINECO under projects MAT2014-46649-C4-1/2-P.

Published
2016
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28. Ordered Helium Trapping and Bonding in Compressed Arsenolite: Synthesis of As4O6·2He

Author

Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, Popescu, Catalin, Cuenca Gotor, Vanesa Paula, Gomis, Oscar, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Contreras García, Julia, Pellicer Porres, Julio, Pereira, A.L.J., Santamaría Pérez, David, Segura, Alfredo, Instituto de Diseño para la Fabricación y Producción Automatizada, Universitat Politècnica de València (UPV), ALBA-CELLS, Centro de Tecnologías Físicas [Universitat Politècnica de València], Departamento de Física, Universidad de La Laguna, Laboratoire de chimie théorique (LCT), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Universitari de Ciencia dels Materials (ICMUV), Universitat de València (UV), Laboratòrio de Materiais Cerâmicos Avançados, Universidade Federal da Grande Dourados, and Universidad de La Laguna [Tenerife - SP] (ULL)

Subjects
[PHYS]Physics [physics], High-pressure, AS2O3, Compressibility, FISICA APLICADA, TEORIA DE LA SEÑAL Y COMUNICACIONES, Glass, Refinement, VAN
Abstract

Compression of arsenolite has been studied from a joint experimental and theoretical point of view. Experiments on this molecular solid at high pressures with different pressure-transmitting media have been interpreted thanks to state-of-the-art ab initio calculations. Our results confirm arsenolite as one of the most compressible minerals and provide evidence for ordered helium trapping above 3 GPa between adamantane-type As4O6 cages. Our calculations indicate that, at relatively small pressures, helium establishes rather localized structural bonds with arsenic forming a compound with stoichiometry As4O6 center dot 2He. All properties of As4O6 center dot 2He are different from those of parent As4O6. In particular, pressure-induced amorphization, which occurs in arsenolite above 15 GPa, is impeded in As4O6 center dot 2He, thus resulting in a mechanical stability of As4O6 center dot 2He beyond 30 GPa. Our work paves the way to explore the formation of alternative compounds by pressure-induced trapping and reaction of gases, small atomic or molecular species, in the voids of molecular solids containing active lone electron pairs., We acknowledge financial support from the Spanish Consolider Ingenio 2010 Program (Project No. MAT2015-71070-REDC). The work was also supported by Spanish MINECO under Projects No. MAT2014-46649-C4-1/2/3-P and from Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia under Projects No. SP20140701 and No. SP20140871. Supercomputer time has been provided by the Red Espanola de Supercomputacion (RES) and the MALTA cluster. J.A.S. acknowledges Juan de la Cierva fellowship program for his financial support. A.M. and P.R.-H. acknowledge S. Munoz Rodriguez for providing them with a data parsing application. A.L.J.P. acknowledges financial support through Brazilian CNPq (Project No. 201050/2012-9).

Published
2016
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29. Structural Evolution of CO2-Filled Pure Silica LTA Zeolite under High-Pressure High-Temperature Conditions

Author

Santamaría-Pérez, David, primary, Marqueño, Tomas, additional, MacLeod, Simon, additional, Ruiz-Fuertes, Javier, additional, Daisenberger, Dominik, additional, Chuliá-Jordan, Raquel, additional, Errandonea, Daniel, additional, Jordá, Jose Luis, additional, Rey, Fernando, additional, McGuire, Chris, additional, Mahkluf, Adam, additional, Kavner, Abby, additional, and Popescu, Catalin, additional

Published
2017
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30. Experimental and Theoretical Study of SbPO4under Compression

Author

Pereira, André Luis de Jesus, Santamaría-Pérez, David, Vilaplana, Rosário, Errandonea, Daniel, Popescu, Catalin, da Silva, Estelina Lora, Sans, Juan Angel, Rodríguez-Carvajal, Juan, Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Mujica, Andres, Radescu, Silvana Elena, Beltrán, Armando, Otero-de-la-Roza, Alberto, Nalin, Marcelo, Mollar, Miguel, and Manjón, Francisco Javier

Abstract

SbPO4is a complex monoclinic layered material characterized by a strong activity of the nonbonding lone electron pair (LEP) of Sb. The strong cation LEP leads to the formation of layers piled up along the aaxis and linked by weak Sb–O electrostatic interactions. In fact, Sb has 4-fold coordination with O similarly to what occurs with the P–O coordination, despite the large difference in ionic radii and electronegativity between both elements. Here we report a joint experimental and theoretical study of the structural and vibrational properties of SbPO4at high pressure. We show that SbPO4is not only one of the most compressible phosphates but also one of the most compressible compounds of the ABO4family. Moreover, it has a considerable anisotropic compression behavior, with the largest compression occurring along a direction close to the aaxis and governed by the compression of the LEP and the weak interlayer Sb–O bonds. The strong compression along the aaxis leads to a subtle modification of the monoclinic crystal structure above 3 GPa, leading from a 2D to a 3D material. Moreover, the onset of a reversible pressure-induced phase transition is observed above 9 GPa, which is completed above 20 GPa. We propose that the high-pressure phase is a triclinic distortion of the original monoclinic phase. The understanding of the compression mechanism of SbPO4can aid to improve the ion intercalation and catalytic properties of this layered compound.

Published
2020
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31. Metastable structural transformations and pressure-induced amorphization in natural (Mg,Fe)2SiO4 olivine under static compression: A Raman spectroscopic study

Author

Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Economía y Competitividad, UK Research and Innovation, Natural Environment Research Council, Reino Unido, Santamaría Pérez, David, Thomson, Andrew, Segura, Alfredo, Pellicer Torres, Julio, Manjón, Francisco-Javier, Cora, Furio, McColl, Kit, Wilson, Mark, Dobson, David, McMillan, Paul, Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Economía y Competitividad, UK Research and Innovation, Natural Environment Research Council, Reino Unido, Santamaría Pérez, David, Thomson, Andrew, Segura, Alfredo, Pellicer Torres, Julio, Manjón, Francisco-Javier, Cora, Furio, McColl, Kit, Wilson, Mark, Dobson, David, and McMillan, Paul

Abstract

[EN] Raman spectroscopic data were obtained for (Mg,Fe)(2)SiO4 samples during compression to 57 GPa. Single crystals of San Carlos olivine compressed hydrostatically above 41 GPa showed appearance of a new "defect" peak in the 820-840 cm(-1) region associated with SiOSi linkages appearing between adjacent SiO44- tetrahedra to result in five- or sixfold-coordinated silicate species. Appearance of this feature is accompanied by a broad amorphous background. The changes occur at lower pressure than metastable crystalline transitions of end-member Mg2SiO4 forsterite (Fo-I) into Fo-II and Fo-III phases described recently. We complemented our experimental study using density functional theory (DFT) calculations and anisotropic ion molecular dynamics (AIMD) simulations to study the Raman spectra and vibrational density of states (VDOS) of metastably compressed Mg2SiO4 olivine, Fo-II and Fo-III, and quenched melts at high and low pressures. By 54 GPa all sharp crystalline peaks disappeared from observed Raman spectra indicating complete pressure-induced amorphization (PIA). The amorphous (Mg,Fe)(2)SiO4 spectrum contains Si-O stretching bands at lower wavenumber than expected for SiO44- indicating high coordination of the silicate units. The amorphous spectrum persisted on decompression to ambient conditions but with evidence for reappearance of tetrahedrally coordinated units. Non hydrostatic compression of polycrystalline olivine samples showed similar appearance of the defect feature and broad amorphous features between 43-44 GPa. Both increased in intensity as the sample was left at pressure overnight but they disappeared during decompression below 17 GPa with recovery of the starting olivine Raman signature. A hydrated San Carlos olivine sample containing 75-150 ppm OH was also studied. Significant broadening of the SiO44- stretching peaks was observed above 43 GPa but without immediate appearance of the defect or broad amorphous features. However, both of these charact

Published
2016

32. Ordered helium trapping and bonding in compressed arsenolite: Synthesis of As4O6 2He

Author

Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Economía y Competitividad, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, Universitat Politècnica de València, Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, Popescu, Catalin, Cuenca Gotor, Vanesa Paula, Gomis, Oscar, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Contreras García, Julia, Pellicer Porres, Julio, Pereira, A.L.J., Santamaría Pérez, David, Segura, Alfredo, Universitat Politècnica de València. Departamento de Comunicaciones - Departament de Comunicacions, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Economía y Competitividad, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, Universitat Politècnica de València, Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, Popescu, Catalin, Cuenca Gotor, Vanesa Paula, Gomis, Oscar, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Contreras García, Julia, Pellicer Porres, Julio, Pereira, A.L.J., Santamaría Pérez, David, and Segura, Alfredo

Abstract

Compression of arsenolite has been studied from a joint experimental and theoretical point of view. Experiments on this molecular solid at high pressures with different pressure-transmitting media have been interpreted thanks to state-of-the-art ab initio calculations. Our results confirm arsenolite as one of the most compressible minerals and provide evidence for ordered helium trapping above 3 GPa between adamantane-type As4O6 cages. Our calculations indicate that, at relatively small pressures, helium establishes rather localized structural bonds with arsenic forming a compound with stoichiometry As4O6 center dot 2He. All properties of As4O6 center dot 2He are different from those of parent As4O6. In particular, pressure-induced amorphization, which occurs in arsenolite above 15 GPa, is impeded in As4O6 center dot 2He, thus resulting in a mechanical stability of As4O6 center dot 2He beyond 30 GPa. Our work paves the way to explore the formation of alternative compounds by pressure-induced trapping and reaction of gases, small atomic or molecular species, in the voids of molecular solids containing active lone electron pairs.

Published
2016

33. Pressure-induced amorphization of YVO4:Eu3+ nanoboxes

Author

Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Educación y Ciencia, Fundación CajaCanarias, Deutsche Forschungsgemeinschaft, Ministerio de Economía y Competitividad, Alexander von Humboldt Foundation, European Regional Development Fund, Ruiz Fuertes, Javier, Gomis, O., León Luis, S. F., Schrodt, N., Manjón Herrera, Francisco Javier, Ray, Sudeshna, Santamaría Pérez, David, Sans Tresserras, Juan Ángel, Ortiz, H. M., Errandonea, Daniel, Ferrer Roca, Chantal, Segura, A., Martínez García, Domingo, Lavin, V., Rodríguez Mendoza, U. R., Muñoz, A., Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Educación y Ciencia, Fundación CajaCanarias, Deutsche Forschungsgemeinschaft, Ministerio de Economía y Competitividad, Alexander von Humboldt Foundation, European Regional Development Fund, Ruiz Fuertes, Javier, Gomis, O., León Luis, S. F., Schrodt, N., Manjón Herrera, Francisco Javier, Ray, Sudeshna, Santamaría Pérez, David, Sans Tresserras, Juan Ángel, Ortiz, H. M., Errandonea, Daniel, Ferrer Roca, Chantal, Segura, A., Martínez García, Domingo, Lavin, V., Rodríguez Mendoza, U. R., and Muñoz, A.

Abstract

This is an author-created, un-copyedited version of an article published in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0957-4484/27/2/025701, A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu3+ nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4. These results are confirmed both by Raman spectroscopy and Eu3+ photoluminescence which detect the phase transition to a scheelite-type structure at 10.1 and 9.1 GPa, respectively. The irreversibility of the phase transition is observed with the three techniques after a maximum pressure in the upstroke of around 20 GPa. The existence of two D-5(0)-> F-7(0) photoluminescence peaks confirms the existence of two local environments for Eu3+, at least for the low-pressure phase. One environment is the expected for substituting Y3+ and the other is likely a disordered environment possibly found at the surface of the nanoboxes.

Published
2016

34. Effect of pressure on La2(WO4)3 with a modulated scheelite-type structure

Author

Sabalisck, N.P., Lopez Solano, Javier, Guzmán-Afonso, C., Santamaría Pérez, David, González-Silgo, C., Mújica, Andrés, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Radescu, Silvana, Vendrell, X., Mestres, L., Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, and Universitat de Barcelona

Subjects
Eu binary oxides, Optical properties, Ferromagnetisme, X-rays diffraction, Terres rares, Amorphization, Espectroscòpia Raman, Awo(4), X-ray, Augmented-wave method, FISICA APLICADA, Rare earths, Crystal stability, Raman spectroscopy, Ferromagnetism, Difracció de raigs X, Propietats òptiques, Induced phase-transitions, Raman
Abstract

We have studied the effect of pressure on the structural and vibrational properties of lanthanum tritungstate La2(WO4)3. This compound crystallizes under ambient conditions in the modulated scheelite-type structure known as the α phase. We have performed x-ray diffraction and Raman scattering measurements up to a pressure of 20 GPa, as well as ab initio calculations within the framework of the density functional theory. Up to 5 GPa, the three methods provide a similar picture of the evolution under pressure of α-La2(WO4)3. At 5 GPa, we begin to observe some structural changes, and above 6 GPa we find that the x-ray patterns cannot be indexed as a single phase. However, we find that a mixture of two phases with C2/c symmetry accounts for all diffraction peaks. Our ab initio study confirms the existence of several C2/c structures, which are very close in energy in this compression range. According to our measurements, a state with medium-range order appears at pressures above 9 and 11 GPa, from x-ray diffraction and Raman experiments, respectively. Based upon our theoretical calculations we propose several high-pressure candidates with high cationic coordinations at these pressures. The compound evolves into a partially amorphous phase at pressures above 20 GPa., We acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad under Grants MAT2010-21270-C04-02/03/04, CTQ2009-14596-C02-01, CSD2007-00045 and the Comunidad de Madrid and European Social Fund S2009/PPQ-1551-4161893. Access to the MALTA Cluster Computer (Universidad de Oviedo), the Atlante Super-computer (Instituto Tecnologico de Canarias, Red Espanola de Supercomputacion), and the MALTA Xcalibur Diffractometer (Universidad Complutense de Madrid) is gratefully acknowledged. C. G. A. wishes to thank the Agencia Canaria de Investigacion, Innovacion y Sociedad de la Informacion, and the European Social Fund of the Gobierno de Canarias for a fellowship. J.A.S. acknowledges financial support through the Juan de la Cierva fellowship program.

Published
2014

35. Ordered helium trapping and bonding in compressed arsenolite: Synthesis ofAs4O6·2He

Author

Sans, Juan A., primary, Manjón, Francisco J., additional, Popescu, Catalin, additional, Cuenca-Gotor, Vanesa P., additional, Gomis, Oscar, additional, Muñoz, Alfonso, additional, Rodríguez-Hernández, Plácida, additional, Contreras-García, Julia, additional, Pellicer-Porres, Julio, additional, Pereira, Andre L. J., additional, Santamaría-Pérez, David, additional, and Segura, Alfredo, additional

Published
2016
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36. Crystal structure of sinhalite MgAlBO4 under high pressure

Author

Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Educación y Ciencia, Ministerio de Economía y Competitividad, Comunidad de Madrid, Generalitat Valenciana, Ministerio de Ciencia e Innovación, Santamaría Pérez, David, Errandonea, Daniel, Gomis, O., Sans Tresserras, Juan Ángel, Pereira, A. L. J., Manjón Herrera, Francisco Javier, Popescu, Catalin, Rodríguez Hernández, Plácida, Muñoz, Alfonso, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Educación y Ciencia, Ministerio de Economía y Competitividad, Comunidad de Madrid, Generalitat Valenciana, Ministerio de Ciencia e Innovación, Santamaría Pérez, David, Errandonea, Daniel, Gomis, O., Sans Tresserras, Juan Ángel, Pereira, A. L. J., Manjón Herrera, Francisco Javier, Popescu, Catalin, Rodríguez Hernández, Plácida, and Muñoz, Alfonso

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp512131e, We report on high-pressure angle-dispersive X-ray diffraction data up to 27 GPa for natural MgAlBO4 sinhalite mineral and ab initio total energy calculations. The experimental bulk modulus of sinhalite is B-0 = 171(3) GPa with a first-pressure derivative of B-0' = 4.2(3). A comparison with other olivine-type compounds shows that the value for B0 is 27% larger than that of Mg2SiO4 forsterite and 29% smaller than that of Al2BeO4 chrysoberyl. These differences are interpreted, on the basis of our ab initio calculations, in terms of the relative incompressibility of Al-O bonds in AlO6 octahedra (with a calculated bulk modulus of 250(1) GPa) as compared to Mg-O bonds in MgO6 octahedra (with a calculated bulk modulus of 130(1) GPa). The spatial cation distribution in the Pbnm orthorhombic unit cell and different polyhedral compressibilities entails a strong anisotropic compression comparable to that of forsterite. The axial compressibilities are 1.06(2) x 10(-3), 2.17(2) x 10(-3), and 1.30(3) x 10(-3) GPa(-1) for a, b, and c axes, respectively. The crystal chemistry of sinhalite under compression is compared to that of other olivine-like compounds. Compressibility trends and possible high-pressure phases are discussed.

Published
2015

37. Experimental and theoretical investigations on structural and vibrational properties of melilite-type Sr2ZnGe2O7 at high pressure and delineation of a high pressure monoclinic phase

Author

Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Achary, S. Nagabhusan, Errandonea, Daniel, Santamaría-Pérez, David, Gomis, O., Patwe, Sadiqua J., Manjón Herrera, Francisco Javier, Rodríguez Hernández, Plácida, Muñoz, Alfonso, Tyagi, Avesh Kumar, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Achary, S. Nagabhusan, Errandonea, Daniel, Santamaría-Pérez, David, Gomis, O., Patwe, Sadiqua J., Manjón Herrera, Francisco Javier, Rodríguez Hernández, Plácida, Muñoz, Alfonso, and Tyagi, Avesh Kumar

Abstract

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.inorgchem.5b00937", We report a combined experimental and theoretical study of melilite-type germanate, Sr2ZnGe2O7, under compression. In situ high-pressure X-ray diffraction and Raman scattering measurements up to 22 GPa were complemented with first-principles theoretical calculations of structural and lattice dynamics properties. Our experiments show that the tetragonal structure of Sr2ZnGe2O7 at ambient conditions transforms reversibly to a monoclinic phase above 12.2 Gpa with similar to 1% volume drop at the phase transition pressure. Density functional calculations indicate the transition pressure at, similar to 13 GPa, which agrees well with the experimental value. The structure of the high-pressure monoclinic phase is closely related to the ambient pressure phase and results from a displacive-type phase transition. Equations of state of both tetragonal and monoclinic phases are reported. Both of the phases show anisotropic compressibility with a larger compressibility in the direction perpendicular to the [ZnGe2O7](2-) sheets than along the sheets. Raman-active phonons of both the tetragonal and monoclinic phases and their pressure dependences were also determined. Tentative assignments of the Raman modes of the tetragonal phase were discussed in the light of lattice dynamics calculations. A possible irreversible second phase transition to a highly disordered or amorphous state is detected in Raman scattering measurements above 21 GPa.

Published
2015

38. Exploring the high-pressure behavior of the three known polymorphs of BiPO4: Discovery of a new polymorph

Author

Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Generalitat Valenciana, Ministerio de Economía y Competitividad, Ministerio de Educación y Ciencia, Errandonea, Daniel, Gomis, O., Santamaría Pérez, David, García-Domene, B., Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Achary, S. N., Tyagi, A. K., Popescu, Catalin, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Generalitat Valenciana, Ministerio de Economía y Competitividad, Ministerio de Educación y Ciencia, Errandonea, Daniel, Gomis, O., Santamaría Pérez, David, García-Domene, B., Muñoz, Alfonso, Rodríguez-Hernández, Plácida, Achary, S. N., Tyagi, A. K., and Popescu, Catalin

Abstract

The following article appeared in Journal of Applied Physics and may be found at http://dx.doi.org/10.1063/1.4914407 . Authors own version of final article on e-print servers, We have studied the structural behavior of bismuth phosphate under compression. We performed x-ray powder diffraction measurements up to 31.5 GPa and ab initio calculations. Experiments were carried out on different polymorphs: trigonal (phase I) and monoclinic (phases II and III). Phases I and III, at low pressure (P < 0.2-0.8 GPa), transform into phase II, which has a monazite-type structure. At room temperature, this polymorph is stable up to 31.5 GPa. Calculations support these findings and predict the occurrence of an additional transition from the monoclinic monazite-type to a tetragonal scheelite-type structure (phase IV). This transition was experimentally found after the simultaneous application of pressure (28 GPa) and temperature (1500 K), suggesting that at room temperature the transition might by hindered by kinetic barriers. Calculations also predict an additional phase transition at 52 GPa, which exceeds the maximum pressure achieved in the experiments. This transition is from phase IV to an orthorhombic barite-type structure (phase V). We also studied the axial and bulk compressibility of BiPO4. Room-temperature pressure-volume equations of state are reported. BiPO4 was found to be more compressible than isomorphic rare-earth phosphates. The discovered phase IV was determined to be the less compressible polymorph of BiPO4. On the other hand, the theoretically predicted phase V has a bulk modulus comparable with that of monazite-type BiPO4. Finally, the isothermal compressibility tensor for the monazite-type structure is reported at 2.4 GPa showing that the direction of maximum compressibility is in the (0 1 0) plane at approximately 15 degrees (21 degrees) to the a axis for the case of our experimental (theoretical) study. (C) 2015 AIP Publishing LLC.

Published
2015

40. Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In)

Author

Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Generalitat Valenciana, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Santamaría Pérez, David, Gomis Hilario, Oscar, Sans, Juan Ángel, Ortiz, H. M., Vegas, Ángel, Errandonea, Daniel, Ruiz-Fuertes, Javier, Martínez-García, Domingo, García-Domene, B., Pereira, ALJ, Manjón Herrera, Francisco Javier, Rodríguez-Hernández, Placida, Muñoz, A., Piccinelli, F., Bettinelli, M., Popescu, C., Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Generalitat Valenciana, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Santamaría Pérez, David, Gomis Hilario, Oscar, Sans, Juan Ángel, Ortiz, H. M., Vegas, Ángel, Errandonea, Daniel, Ruiz-Fuertes, Javier, Martínez-García, Domingo, García-Domene, B., Pereira, ALJ, Manjón Herrera, Francisco Javier, Rodríguez-Hernández, Placida, Muñoz, A., Piccinelli, F., Bettinelli, M., and Popescu, C.

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C , copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp4124259, The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO(6)] octahedral group and depends on the size of the trivalent A cations. An analysis of the relationship between isomorphic borates and carbonates is also presented, which points to the potentiality of considering borates as chemical analogues of the carbonate mineral family.

Published
2014

41. Pbca-Type In2O3: the high-pressure post-corundum phase at room temperature

Author

Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Ministerio de Economía y Competitividad, Generalitat Valenciana, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, García-Domene, B., Sans Tresserras, Juan Ángel, Gomis, O., Manjón Herrera, Francisco Javier, Ortiz, H. M., Errandonea, Daniel, Santamaría Pérez, David, Martinez-Garcia, D., Vilaplana Cerda, Rosario Isabel, Pereira, A. L. J., Morales-Garcia, A., Rodríguez Hernández, Plácida, Muñoz, Alfonso, Popescu, Catalin, Segura, A., Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Ministerio de Economía y Competitividad, Generalitat Valenciana, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasil, García-Domene, B., Sans Tresserras, Juan Ángel, Gomis, O., Manjón Herrera, Francisco Javier, Ortiz, H. M., Errandonea, Daniel, Santamaría Pérez, David, Martinez-Garcia, D., Vilaplana Cerda, Rosario Isabel, Pereira, A. L. J., Morales-Garcia, A., Rodríguez Hernández, Plácida, Muñoz, Alfonso, Popescu, Catalin, and Segura, A.

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp5061599, High-pressure powder X-ray diffraction and Raman scattering measurements in cubic bixbyite-type indium oxide (c-In2O3) have been performed at room temperature. On increasing pressure c-In2O3 undergoes a transition to the Rh2O3-II structure but on decreasing pressure Rh2O3-II-type In2O3 undergoes a transition to a previously unknown phase with Pbca space group which is isostructural to Rh2O3-III. On further decrease of pressure, we observed a phase transition to the metastable corundum-type In2O3 near room conditions. Recompression of the metastable corundum-type In2O3 at room temperature leads to a transition to the Rh2O3-III phase, thus showing that the Rh2O3-III phase is the post-corundum phase at room temperature. Our results are supported by theoretical ab initio calculations. Furthermore, they show that the Rh2O3-III phase could be present in other sesquioxides, thus prompting to a revision of the pressure-temperature phase diagrams of sesquioxides

Published
2014

42. Structural and vibrational study of pseudocubic CdIn2Se4 under compression

Author

Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Economía y Competitividad, Generalitat Valenciana, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Santamaría Pérez, David, Gomis, O., Pereira, A. L. J., Vilaplana Cerda, Rosario Isabel, Popescu, Catalin, Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, Rodríguez Hernández, Plácida, Muñoz, Alfonso, Ursaki, Vladislav V., Tiginyanu, Ion M., Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Ministerio de Economía y Competitividad, Generalitat Valenciana, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Santamaría Pérez, David, Gomis, O., Pereira, A. L. J., Vilaplana Cerda, Rosario Isabel, Popescu, Catalin, Sans Tresserras, Juan Ángel, Manjón Herrera, Francisco Javier, Rodríguez Hernández, Plácida, Muñoz, Alfonso, Ursaki, Vladislav V., and Tiginyanu, Ion M.

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp5077565, We report a comprehensive experimental and theoretical study of the structural and vibrational properties of a-CdIn2Se4 under compression. Angle-dispersive synchrotron X-ray diffraction and Raman spectroscopy evidence that this ordered-vacancy compound with pseudocubic structure undergoes a phase transition (7 GPa) toward a disordered rocksalt structure as observed in many other ordered-vacancy compounds. The equation of state and the pressure dependence of the Raman-active modes of this semiconductor have been determined and compared both to ab initio total energy and lattice dynamics calculations and to related compounds. Interestingly, on decreasing pressure, at similar to 2 GPa, CdIn2Se4 transforms into a spinel structure which, according to calculations, is energetically competitive with the initial pseudocubic phase. The phase behavior of this compound under compression and the structural and compressibility trends in AB(2)Se(4) selenides are discussed.

Published
2014

43. Structural and vibrational properties of CdAl2S4 under high pressure: Experimental and theoretical approach

Author

Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Sans Tresserras, Juan Ángel, Santamaría Pérez, David, Popescu, Catalin, Gomis, O., Manjón Herrera, Francisco Javier, Vilaplana Cerda, Rosario Isabel, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Ursaki, Veacheslav, Tiginyanu, Ivan, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Sans Tresserras, Juan Ángel, Santamaría Pérez, David, Popescu, Catalin, Gomis, O., Manjón Herrera, Francisco Javier, Vilaplana Cerda, Rosario Isabel, Muñoz, Alfonso, Rodríguez Hernández, Plácida, Ursaki, Veacheslav, and Tiginyanu, Ivan

Abstract

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp5037926.”, The behavior of defect chalcopyrite CdAl2S4 at high pressures and ambient temperature has been investigated in a joint experimental and theoretical study. High-pressure X-ray diffraction and Raman scattering measurements were complemented with theoretical ab initio calculations. The equation of state and pressure dependences of the structural parameters of CdAl2S4 were determined and compared to those of other AB(2)X(4) ordered-vacancy compounds. The pressure dependence of the Raman-active mode frequencies is reported, as well as the theoretical phonon dispersion curves and phonon density of states at 1 atm. Our measurements suggest that defect chalcopyrite CdAl2S4 undergoes a phase transition above 15 GPa to a disordered-rocksalt structure, whose equation of state was also obtained up to 25 GPa. In a downstroke from 25 GPa to 1 atm, our measurements indicate that CdAl2S4 does not return to the defect chalcopyrite phase; it partially retains the disordered-rocksalt phase and partially transforms into the spinel structure. The nature of the spinel structure was confirmed by the good agreement of our experimental results with our theoretical calculations. All in all, our experimental and theoretical results provide evidence that the spinel and defect chalcopyrite phases of CdAl2S4 are competitive at 1 atm. This result opens the way to the synthesis of spinel-type CdAl2S4 at near-ambient conditions.

Published
2014

44. Structural Evolution of CO2-Filled Pure Silica LTA Zeolite under High-Pressure High-Temperature Conditions.

Author

Santamaría-Pérez, David, Marqueño, Tomas, MacLeod, Simon, Ruiz-Fuertes, Javier, Daisenberger, Dominik, Chuliá-Jordan, Raquel, Errandonea, Daniel, Jordá, Jose Luis, Fernando Rey, McGuire, Chris, Mahkluf, Adam, Kavner, Abby, and Popescu, Catalin

Subjects
*SILICA, *ZEOLITES, *HIGH temperatures, *HIGH pressure (Science), *CRYSTAL structure, *CARBON monoxide
Abstract

The crystal structure of CO2-filled pure-SiO2 LTA zeolite has been studied at high pressures and temperatures using synchrotron-based X-ray powder diffraction. Its structure consists of 13 CO2 guest molecules, 12 of them accommodated in the large α-cages and one in the β-cages, giving a SiO2/CO2 stoichiometric ratio smaller than 2. The structure remains stable under pressure up to 20 GPa with a slight pressure-dependent rhombohedral distortion, indicating that pressure-induced amorphization is prevented by the insertion of guest species in this open framework. The ambient-temperature lattice compressibility has been determined. In situ high-pressure resistive-heating experiments up to 750 K allow us to estimate the thermal expansivity at P ≈ 5 GPa. Our data confirm that the insertion of CO2 reverses the negative thermal expansion of the empty zeolite structure. No evidence of any chemical reaction was observed. The possibility of synthesizing a silicon carbonate at high temperatures and higher pressures is discussed in terms of the evolution of C-O and Si-O distances between molecular and framework atoms. [ABSTRACT FROM AUTHOR]

Published
2017
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45. The Zintl–Klemm Concept Applied to Cations in Oxides. II. The Structures of Silicates

Author

Santamaría Pérez, David, Vegas, Ángel, and Liebau, Friedrich

Subjects
Cation arrays, Silicates, Zintl-Klemm concept, Zintl phases, Structures
Abstract

The structures of ternary and quaternary silicates are revisited on the basis of the Zintl–Klemm concept and the Pearson's generalised octet rule. The three-dimensional skeletons formed by the Si atoms can be interpreted as if the Si atoms were behaving as Zintl polyanions, adopting the structure of either main-group elements or Zintl polyanions showing the same connectivity. The O atoms are then located close to both, the hypothetical two-electron bonds and the lone pairs, giving rise to a tetrahedral coordination. In some silicates, the Si atoms clearly show an amphoteric character so that some Si atoms act as donors (bases) adopting an octahedral coordination, whereas others behave as acceptors (acid), adopting a tetrahedral coordination. Although the octahedral coordination seems to be favoured by the application of pressure, the results reported here indicate that the coordination sphere of silicon is not a function of the assumed ionic radius of the Si4+ cations but it depends on the nature of the other cations accompanying them in the structure., The present work was supported by DGI of MEC (Spain) under project MAT2004-05867-C03-02.

Published
2005

47. Structural and Vibrational Study of Pseudocubic CdIn2Se4 under Compression

Author

Santamaría-Pérez, David, primary, Gomis, Oscar, additional, Pereira, André L. J., additional, Vilaplana, Rosario, additional, Popescu, Catalin, additional, Sans, Juan Angel, additional, Manjón, Francisco Javier, additional, Rodríguez-Hernández, Placida, additional, Muñoz, Alfonso, additional, Ursaki, Vladislav V., additional, and Tiginyanu, Ion M., additional

Published
2014
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49. Compressibility Systematics of Calcite-Type Borates: An Experimental and Theoretical Structural Study on ABO3 (A = Al, Sc, Fe, and In)

Author

Santamaría-Pérez, David, primary, Gomis, Oscar, additional, Sans, Juan Angel, additional, Ortiz, Henry. M., additional, Vegas, Ángel, additional, Errandonea, Daniel, additional, Ruiz-Fuertes, Javier, additional, Martinez-Garcia, Domingo, additional, Garcia-Domene, Braulio, additional, Pereira, André L. J., additional, Manjón, Francisco Javier, additional, Rodríguez-Hernández, Placida, additional, Muñoz, Alfonso, additional, Piccinelli, Fabio, additional, Bettinelli, Marco, additional, and Popescu, Catalin, additional

Published
2014
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50. Phase behaviour of Ag2CrO4 under compression: Structural, vibrational, and optical properties

Author

Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Comunidad de Madrid, Santamaría Pérez, David, Bandiello, Enrico, Errandonea, Daniel, Ruiz-Fuertes, Javier, Gomis Hilario, Oscar, Sans, Juan Ángel, Manjón Herrera, Francisco Javier, Rodríguez-Hernández, Plácida, Muñoz, Alfonso, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Universitat Politècnica de València. Instituto de Diseño para la Fabricación y Producción Automatizada - Institut de Disseny per a la Fabricació i Producció Automatitzada, Universitat Politècnica de València. Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica - Centre de Tecnologies Físiques: Acústica, Materials i Astrofísica, Ministerio de Educación y Ciencia, Ministerio de Ciencia e Innovación, Universitat Politècnica de València, Comunidad de Madrid, Santamaría Pérez, David, Bandiello, Enrico, Errandonea, Daniel, Ruiz-Fuertes, Javier, Gomis Hilario, Oscar, Sans, Juan Ángel, Manjón Herrera, Francisco Javier, Rodríguez-Hernández, Plácida, and Muñoz, Alfonso

Abstract

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp401524s, We have performed an experimental study of the crystal structure, lattice dynamics, and optical properties of silver chromate (Ag2CrO4) at ambient temperature and high pressures. In particular, the crystal structure, Raman-active phonons, and electronic band gap have been accurately determined. When the initial orthorhombic Pnma Ag2CrO4 structure (phase I) is compressed up to 4.5 GPa, a previously undetected phase (phase II) has been observed with a 0.95% volume collapse. The structure of phase II can be indexed to a similar orthorhombic cell as phase I, and the transition can be considered to be an isostructural transition. This collapse is mainly due to the drastic contraction of the a axis (1.3%). A second phase transition to phase III occurs at 13 GPa to a structure not yet determined. First-principles calculations have been unable to reproduce the isostructural phase transition, but they propose the stabilization of a spinel-type structure at 11 GPa. This phase is not detected in experiments probably because of the presence of kinetic barriers. Experiments and calculations therefore seem to indicate that a new structural and electronic description is required to model the properties of silver chromate.

Published
2013

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