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Your search keyword '"Martinez-Garcia, Domingo"' showing total 18 results
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18 results on '"Martinez-Garcia, Domingo"'

1. 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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3. 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

5. Pressure-induced order-disorder transitions in beta-In2S3 : an experimental and theoretical study of structural and vibrational properties

Author

Gallego-Parra, Samuel, Gomis, Oscar, Vilaplana, Rosario, Paula Cuenca-Gotor, Vanesa, Martinez-Garcia, Domingo, Rodriguez-Hernandez, Placida, Munoz, Alfonso, Romero, Aldo, Majumdar, Arnab, Ahuja, Rajeev, Popescu, Catalin, Javier Manjon, Francisco, Gallego-Parra, Samuel, Gomis, Oscar, Vilaplana, Rosario, Paula Cuenca-Gotor, Vanesa, Martinez-Garcia, Domingo, Rodriguez-Hernandez, Placida, Munoz, Alfonso, Romero, Aldo, Majumdar, Arnab, Ahuja, Rajeev, Popescu, Catalin, and Javier Manjon, Francisco

Abstract

This joint experimental and theoretical study of the structural and vibrational properties of beta-In2S3 upon compression shows that this tetragonal defect spinel undergoes two reversible pressure-induced order-disorder transitions up to 20 GPa. We propose that the first high-pressure phase above 5.0 GPa has the cubic defect spinel structure of alpha-In2S3 and the second high-pressure phase (phi-In2S3) above 10.5 GPa has a defect alpha-NaFeO2-type (R3m) structure. This phase, related to the NaCl structure, has not been previously observed in spinels under compression and is related to both the tetradymite structure of topological insulators and to the defect LiTiO2 phase observed at high pressure in other thiospinels. Structural characterization of the three phases shows that alpha-In2S3 is softer than beta-In2S3 while phi-In2S3 is harder than beta-In2S3. Vibrational characterization of the three phases is also provided, and their Raman-active modes are tentatively assigned. Our work shows that the metastable alpha phase of In2S3 can be accessed not only by high temperature or varying composition, but also by high pressure. On top of that, the pressure-induced beta-alpha-phi sequence of phase transitions evidences that beta-In2S3, a BIII2XV3 compound with an intriguing structure typical of A(II)BIII(2)XVI(4) compounds (intermediate between thiospinels and ordered-vacancy compounds) undergoes: (i) a first phase transition at ambient pressure to a disordered spinel-type structure (alpha-In2S3), isostructural with those found at high pressure and high temperature in other BIII2XV3 compounds; and (ii) a second phase transition to the defect alpha-NaFeO2-type structure (phi-In2S3), a distorted NaCl-type structure that is related to the defect NaCl phase found at high pressure in A(II)BIII(2)XVI(4) ordered-vacancy compounds and to the defect LiTiO2-type phase found at high pressure in A(II)BIII(2)XVI(4) thiospinels. This result shows that In2S3 (with its intrinsic vacanci

Published
2021
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8. Pressure Impact on the Stability and Distortion of the Crystal Structure of CeScO3

Author

Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Economía y Competitividad, Errandonea, Daniel, Santamaria-Perez, David, Martinez-Garcia, Domingo, Gomis, O., Shukla, Rakesh, Achary, S. Nagabhusan, Tyagi, Avesh K., Popescu, Catalin, Universitat Politècnica de València. Departamento de Física Aplicada - Departament de Física Aplicada, Ministerio de Economía y Competitividad, Errandonea, Daniel, Santamaria-Perez, David, Martinez-Garcia, Domingo, Gomis, O., Shukla, Rakesh, Achary, S. Nagabhusan, Tyagi, Avesh K., and Popescu, Catalin

Abstract

[EN] The effects of high pressure on the crystal structure of orthorhombic (Pnma) perovskite-type cerium scandate were studied in situ under high pressure by means of synchrotron X-ray powder diffraction, using a diamond-anvil cell. We 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 indicated an anisotropic compression. The room-temperature pressure¿volume equation of state (EOS) obtained from the experiments indicated the EOS parameters V0 = 262.5(3) Å3 , B0 = 165(7) GPa, and B0¿ = 6.3(5). From the evolution of microscopic structural parameters like bond distances and coordination polyhedra of cerium and scandium, the macroscopic behavior of CeScO3 under compression was explained and reasoned for its large pressure stability. The reported results are discussed in comparison with high-pressure results from other

Published
2017

12. 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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15. Portable multi-anvil device for in situ angle-dispersive synchrotron diffraction measurements at high pressure and temperature.

Author

Le Godec, Yann, Hamel, Gerard, Solozhenko, Vladimir L., Martinez-Garcia, Domingo, Philippe, Julien, Hammouda, Tahar, Mezouar, Mohamed, Crichton, Wilson A., Morard, Guillaume, and Klotzz, Stefan

Subjects
SYNCHROTRON radiation, X-ray diffraction, HIGH pressure chemistry, HIGH temperature chemistry, INDUSTRIAL chemistry
Abstract

A recently developed portable multi-anvil device for in situ angle-dispersive synchrotron diffraction studies at pressures up to 25 GPa and temperatures up to 2000 K is described. The system consists of a 450 ton V7 Paris-Edinburgh press combined with a Stony Brook `T-cup' multi-anvil stage. Technical developments of the various modifications that were made to the initial device in order to adapt the latter to angular-dispersive X-ray diffraction experiments are fully described, followed by a presentation of some results obtained for various systems, which demonstrate the power of this technique and its potential for crystallographic studies. Such a compact large-volume set-up has a total mass of only 100 kg and can be readily used on most synchrotron radiation facilities. In particular, several advantages of this new set-up compared with conventional multi-anvil cells are discussed. Possibilities of extension of the (P, T) accessible domain and adaptation of this device to other in situ measurements are given. [ABSTRACT FROM AUTHOR]

Published
2009
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16. Compressibility Systematics of Calcite-Type Borates: An Experimental and Theoretical Structural Study on ABO3(A = Al, Sc, Fe, and In)

Author

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

Abstract

The structural properties of calcite-type orthoborates ABO3(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 initiototal-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 caxis is roughly three times that along the aaxis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO6] 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
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17. LiCrO2 Under Pressure: In-Situ Structural and Vibrational Studies.

Author

Garg, Alka B., Errandonea, Daniel, Pellicer-Porres, Julio, Martinez-Garcia, Domingo, Kesari, Swayam, Rao, Rekha, Popescu, Catalin, and Bettinelli, Marco

Subjects
X-ray powder diffraction, RAMAN spectroscopy, LITHIUM compounds
Abstract

The high-pressure behaviour of LiCrO2, a compound isostructural to the battery compound LiCoO2, has been investigated by synchrotron-based angle-dispersive X-ray powder diffraction, Raman spectroscopy, and resistance measurements up to 41, 30, and 10 Gpa, respectively. The stability of the layered structured compound on a triangular lattice with R-3m space group is confirmed in all three measurements up to the highest pressure reached. The dependence of lattice parameters and unit-cell volume with pressure has been determined from the structural refinements of X-ray diffraction patterns that are used to extract the axial compressibilities and bulk modulus by means of Birch–Murnaghan equation-of-state fits. The pressure coefficients for the two Raman-active modes, A1g and Eg, and their mode-Grüneisen parameters are reported. The electrical resistance measurements indicate that pressure has little influence in the resistivity up to 10 GPa. The obtained results for the vibrational and structural properties of LiCrO2 under pressure are in line with the published results of the similar studies on the related compounds. Research work reported in this article contributes significantly to enhance the understanding on the structural and mechanical properties of LiCrO2 and related lithium compounds. [ABSTRACT FROM AUTHOR]

Published
2019
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18. Evaluation of Student Using Telematic Solutions: The Questionnaires' Project

Author

Enric Valor, Tena Sanguesa, Fernando, Pedros Esteban, Roberto, Martinez Lozano, Jose Antonio, Coll Company, Cesar, Del Pilar Utrillas Esteban, Maria, Roldan Garcia, Clodoaldo, Munoz Sanjose, Vicente, Martinez Garcia, Domingo, Ferrer Roca, Chantal, Cruz Munoz, Jose Luis, and Del Carmen Martinez Tomas, Maria

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