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Isothermal sections of the Ti-Co-Zr ternary system at 1073 K and 1173 K were determined using Ti-Co-Zr diffusion triples and equilibrated alloys with optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) and electron probe micro-analysis (EPMA) techniques. A unknown ternary phase with composition of ～Ti31.3Co37.9Zr30.8 was observed to be stable at both 1073 K and 1173 K. Two continuous solid solutions Co2(Ti, Zr) and Co(Ti, Zr) were formed between the binary intermediate compounds Co2Ti (c) and Co2Zr (c) as well as between the CoTi and CoZr intermediate compounds, respectively. The solubility of Zr in the CoTi2 phase was nearly 55.0 at% at both 1073 K and 1173 K, and the Co11Zr2 phase was proved to be non-existent at 1073 K and 1173 K. Liquid phase was observed at 1173 K and exists with a wide range in the Ti-Zr-rich part.

Phase relationships in the Ge-Mn-Ti ternary system have been studied through alloy samples approach. Assisted with Electron Probe Microanalysis (EPMA) and X-ray diffraction (XRD) techniques, isothermal sections at 973 K, 1073 K and 1173 K of this system were constructed and existence of 2 ternary phases, i.e. GeMnTi and Ge 2 MnTi, were confirmed. In addition, remarkable ternary solubilities in some binary compounds were detected, e.g. Ge in Mn 2 Ti and Mn in Ge 5 Ti 6 can be up to 15 at% and 50 at% at 1173 K, respectively. Furthermore, the substitution of Ti by Mn atoms in Ge 5 Ti 6 was confirmed with Rietveld refinement results of solid solutions, Ge 5 (Mn 0.30 Ti 0.70 ) 6 and Ge 5 (Mn 0.67 Ti 0.33 ) 6 .

Developing new hosts is one of the significant and intriguing aspects in the field of luminescence materials. Herein, we report a novel LiInTi2O6 host for phosphors in solid state lighting. The sub-solidus phase relationships, thermal stability, crystal structure, as well as composition- and temperature-dependent luminescence were investigated and discussed by means of various analytical techniques, including powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), structure solution, photoluminescence excitation (PLE) and emission (PL) spectra, decay lifetime, high-temperature luminescence and chromaticity coordinates. LiInTi2O6 crystallizes in a trigonal unit cell with lattice parameters of a = b = 5.1050(1) A, c = 28.5622(4) A, and Z = 6 in space group Rm (No. 166), consisting of an unusual 12-fold coordination hexagonal prism structural framework. Taking LiInTi2O6 as the host, a series of Dy3+/Tm3+ singly-doped and co-doped phosphors was successfully synthesized. With increasing Dy3+ concentration, the emission colors of LiInTi2O6:Tm3+,Dy3+ phosphors can be appropriately tuned from blue to yellow, going through the white region, based on the principle of energy transfer. Energy transfer efficiencies were calculated and the mechanism was confirmed to follow a resonant-type electric dipole–dipole interaction. A configuration coordinate diagram was employed to explain the thermal quenching behaviour of the white lighting phosphor. Structural characteristics and evolution trends of representative titanates were summarized, providing available information for photo/electrical materials designing.

Phase relations in BaO-In2O3-B2O3 system were experimentally and theoretically studied. Firstly, phase equilibria in B2O3-rich corner at 1298 and 1323 K were measured with EPMA and XRD. Then, thermodynamic assessment was performed based on the measured phase relations in this work and from literatures by CALPHAD method using Thermo-Calc software. The intermediate phases were treated as stoichiometric compounds, and the liquid phase was described by the two-sublattice ionic liquid model (In3+, Ba2+)p(O2−, BO33−, B4O72−, B3O4.5)Q. A set of self-consistent thermodynamic parameters was obtained and the calculated phase diagrams and thermochemical properties conform well to the measurements.

The design and development of novel titanium alloys for structural and biomedical applications require reliable thermodynamic and kinetic databases. In this study, diffusion behaviors of six Ti–X (X = Cr, Hf, Mo, Nb, V, Zr) binary systems were systematically investigated at temperatures from 800 to 1200 °C using a set of five Ti–TiAl–Cr–Hf–Mo–Nb–V–Zr diffusion multiples. Concentration profiles of the six Ti–X binary systems were collected from binary regions of the diffusion multiples using electron probe microanalysis (EPMA). Both interdiffusion and impurity (dilute) diffusion coefficients in the Ti-rich bcc phase of these systems were extracted from the concentration profiles using the forward-simulation method. Twenty impurity diffusion coefficients of all the six elements in bcc Ti as well as Ti in bcc Zr at different temperatures obtained from this study are in excellent agreement with the literature data. The interdiffusion coefficients obtained from this study are also in good agreement with previous literature results. The large amount of new experimental data obtained from this study will be essential for establishing the mobility databases for the design and development of advanced titanium alloys.

A series of Dy 3+ /Tm 3+ singly-doped, Dy 3+ /Tm 3+ co-doped, and Dy 3+ /Tm 3+ /Eu 3+ tri-doped InNbO 4 phosphors have been synthesized by a high-temperature solid-state reaction method. Powder X-ray diffraction (XRD), structure refinement, UV–visible diffuse reflectance (UV-DR) spectrum, photoluminescence excitation (PLE) and emission (PL) spectrum, decay lifetimes and CIE chromaticity coordinate were employed to understand the origins of luminescence properties for synthesized phosphors. Rare-earth activators were determined to be completely dissolved into the host lattice and occupied the 2 e sites deviated from an inversion center by virtue of XRD, structure refinement and photoluminescence features. The photoluminescence excitation spectra of phosphors exhibited a broad excitation band ascribed to charge-transfer of O 2− -Nb 5+ , ranging from 200 to 300 nm, and some characteristic excitation peaks associated with energy level transition of RE ions. Under the excitation of UV light, phosphors presented characteristic emission originating from f - f transition within the 4 f configuration of RE ions. With increasing Dy 3+ concentration, emission colors of InNbO 4 :Tm 3+ , Dy 3+ phosphors can be appropriately tuned from blue to yellow, including almost all the white light region, by means of energy transfer from Tm 3+ to Dy 3+ . Energy transfer rates and efficiencies were calculated according to decay lifetimes and energy transfer mechanism followed a resonant type dipole-dipole interaction with critical distance of 22.23 A between Tm 3+ and Dy 3+ . By compensating a red component of Eu 3+ ion, single-component warm-white-light emitting was realized in InNbO 4 :Tm 3+ ,Dy 3+ ,Eu 3+ phosphors. They might be promising candidates for color-tunable light-conversion components in the fabrication of ultraviolet-pumped warm-white-light emitting diodes (WLEDs) for solid-state lighting. Relationship of crystal structures and luminescence properties for InNbO 4 and YNbO 4 phosphors is as well explicated based on structural analysis.

Through alloy sampling combined with diffusion triple technique, phase equilibria in Al–Ti–Zr ternary system at 1073 K were experimentally determined with electron probe microanalysis (EPMA). Experimental results show that there is a solid solution β(Ti,Zr) which dissolves Al up to 16.3% (mole fraction). Ti and Zr can substitute each other in most Ti–Al and Al–Zr binary intermediate phases to a certain degree while the maximum solubility of Zr in Ti3Al and TiAl reaches up to 17.9% and 4.0% (mole fraction), respectively. The isothermal section consists of 16 single-phased regions, 27 two-phased regions and 14 three-phased regions. No ternary phase was detected.

Lithium vanadium oxides and vanadates have wide attention as cathode materials for Li ion battery applications, but there has been limited study on other cations substituted vanadium compounds, which could have favorable electrochemical properties. Here we report the synthesis and electrochemical properties of aggregated K0.25V2O5 nanobelts and the optimization of the crystalline structure for fast Li ion insertion. We propose a partial melting and self-alignment mechanism to produce the aggregated nanobelts. This material can deliver a high discharge capacity of 232 mA h −1 at 100 mA g−1 and high rate capability. It also exhibits superior long-term cycling performance with no capacity fading over 800 cycles at high current density of 1, 1.5, and 2 A g−1. Remarkably, although some work has been devoted to potassium vanadates, there is little work introducing this class of materials with super long lifespan. The results demonstrate that the as-prepared K0.25V2O5 would be a potential candidate for LIBs.

Mg

The borate Ba

Phase equilibria in Ti–Al–Mo ternary system are of fundamental importance to better acquire the phase-forming regulation of TiAl-based alloys. In this paper, phase relations in this system have been investigated with Ti–TiAl–Mo diffusion triples combined with key equilibrated alloys. Five isothermal sections of the Ti–Al–Mo ternary system at 1473, 1373, 1273, 1173, and 1073 K were experimentally determined by means of electron probe microanalysis, scanning electron microscope, and X-ray diffraction. The TiAl and TiAl3 phases show wide ternary composition ranges, while the solubility of Mo in the Ti3Al and αTi phases is relatively limited. The solubility of Al in the β(Ti, Mo) phase decreases from 49.0 at.% at 1473 K to 39.9 at.% at 1073 K while that of Ti in the AlMo3 phase decreases from 25.4 at.% at 1473 K to 20.8 at.% at 1073 K. Moreover, the ternary compound σ forms at a temperature between 1423 and 1373 K through a peritectoid reaction β(Ti, Mo) + AlMo3 → σ. A peri-eutectoid invariant reaction β(Ti, Mo) + AlMo3 → σ + TiAl3 at 1373–1273 K was further deduced and the existence of another invariant reaction β(Ti, Mo) + TiAl3 → σ + TiAl at a temperature between 1273 and 1173 K was also confirmed. The established phase equilibria of the Ti–Al–Mo ternary system may provide essential data required for the construction of reliable thermodynamic assessment of the Ti–Al–Mo system.

Na 0.282 V 2 O 5 nanorods have been successfully prepared using a facile hydrothermal reaction followed by a calcination treatment, which is then used as a cathode for lithium batteries and sodium batteries for the first time. The crystal structure is refined to be a monoclinic lattice, which contains 3D tunnels along the b -axis. The Na ions are located inside the tunnels and form “pillar effect” to prevent the collapse of the crystal structure. As cathode material for lithium batteries, the Na 0.282 V 2 O 5 nanorods deliver a high discharge specific capacity of 264, 186, 191 and 149 mA h g −1 at the current density of 50, 500, 1000 and 1500 mA g −1 , respectively. The Na 0.282 V 2 O 5 nanorods demonstrate the excellent cycling performance up to 400 cycles at 1 and 1.5 A g −1 . Importantly, as cathode material for sodium batteries, Na 0.282 V 2 O 5 exhibits superior long-term cyclic stability up to 1000 cycles at 0.3 A g −1 . The results of ex-situ XRD, EIS and first-principle calculation indicate that the Na 0.282 V 2 O 5 possesses good electrical conductivity and structural stability. Our work demonstrates that the Na 0.282 V 2 O 5 material could be considered as a potential cathode for lithium-ion batteries, and even sodium ion batteries.

Polycrystalline Mg0.87Cu0.13O powders were synthesized by a sol-gel method using Mg(OH)2·4MgCO3·6H2O and CuCl2 as precursors. The obtained sample was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, inductively coupled plasma-atomic emission spectrometry, and superconducting quantum interference device magnetometer. X-ray diffraction result shows the single phase nature and cubic structure of the obtained Mg0.87Cu0.13O. Rietveld refinement shows that the Cu has substituted the Mg sites in the MgO lattice. Transmission electron microscopy further reveals the single crystalline nature and cubic structure of the obtained Mg0.87Cu0.13O. X-ray photoelectron spectroscopy shows +2 valences of Cu ions in Mg0.87Cu0.13O. Magnetic measurement results reveal paramagnetic order of Mg0.87Cu0.13O in 5–300 K temperature range.

In order to catch up and compare with global competition in fields of industries, we state relevant arguments here as follows. 1) How could materials science meet the challenge of ever-increased development of advanced technologies? 2) The development of basic knowledge for microstructure evolution. 3) Newly-developed and developing industry chains are output of multidisciplinary integration occurred in advanced technologies. 4) What could we learn from global experience of novel materials and their manufacturing and fabrication? 5) Designing Chinese knowledge system of novel materials and their manufacturing and fabrication. 6) Where is our roadmap? What are tasks of emergency and measures of implementation for the 13th Five Year Plan? 7) Creating knowledge system of novel materials and their manufacturing and fabrication is one of the forward-looking strategies to build a strong state with advanced and powerful manufacturing and fabrication system. Implementing the so-called five development concepts of “innovation, harmony, green, open and sharing” is the key factor.

Subsolidus phase equilibrium of Na2O–Sm2O3–B2O3system has been investigated mainly by solid-state reaction and powder X-ray diffraction method. There are nine definite three-phase regions and three ternary compounds determined under present experimental conditions. A novel compound Na3SmB2O6was found and confirmed in this system, along with its two homogeneous compounds Na3REB2O6(RE = Pr, Eu) synthesized for the first time. The indexing results showed that all three compounds crystallize in the monoclinic space groupP21/c(No.14) with the same structure type as both Na3NdB2O6and Na3GdB2O6. The lattice parameters (a, b, andc) of new borates Na3REB2O6(RE = Pr, Sm, Eu) decrease linearly with a decreasing radius of RE ion, which obeys the Lanthanide-contraction rule. The existence of a trigonal BO3group in the Na3REB2O6(RE = Pr, Sm) compounds was confirmed by analysis of their infrared absorption spectra. Thermal stabilities of the three new borates have been investigated.

Isothermal sections at 900, 950 and 1000 °C relating to the borate Ba 3 InB 9 O 18 at BO 1.5 -rich corner in the BO 1.5 –BaO–InO 1.5 system were measured with EPMA and XRD, especially the thermal stability of Ba 3 InB 9 O 18 was studied through melting and quenching method. Results showed that isothermal section at 900 °C contains six two-phase regions and six three-phase regions, while isothermal section at 950 and 1000 °C contains three two-phase regions and three three-phase regions. In addition, Ba 3 InB 9 O 18 melts incongruently into InBO 3 and liquid at ∼1025 °C. Breaking of Ba–O bounds in Ba 3 InB 9 O 18 is the trigger of phase transition. Based on the established isothermal sections, primary crystal region of Ba 3 InB 9 O 18 was determined, which will be benefit to designing composition and process for crystal growth of scintillating material Ba 3 InB 9 O 18 .

GdNbTiO6 is used as a host material for phosphors for the first time. Lanthanide ion (Eu3+/Dy3+) doped GdNbTiO6 phosphors were prepared by solid-state reaction, and the crystal structure, luminescence properties, and relevant luminescence mechanisms were investigated. The crystal structure of Eu3+/Dy3+ doped GdNbTiO6 was refined from powder XRD data by the Rietveld method, which is made up of irregular (Gd/Eu/Dy)3+O813− polyhedra and slightly distorted Nb(Ti)O6 octahedra forming a layered structure. The luminescence properties of the GdNbTiO6:Eu3+/Dy3+ phosphors were studied under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation. The GdNbTiO6 host shows a broad emission band about the 400–650 nm region centered at 509 nm owing to the Nb(Ti)O6 octahedral groups, which has spectral overlap with f–f excitation transitions of Eu3+/Dy3+ in the doped samples. For red phosphor GdNbTiO6:Eu3+, a dominant emission peak at 614 nm was attributed to the 5D0 → 7F2 transition of Eu3+, which confirmed that Eu3+ ions are located at sites without inversion symmetry. The phosphor GdNbTiO6:Dy3+ shows bright yellow-green emission prevailing at 577 nm upon 273 nm excitation. With increasing activator concentration, the emission derived from the characteristic f–f transitions of Eu3+/Dy3+ is enhanced while the host emission is weakened, which is due to the energy transfer from the host to Eu3+/Dy3+. Considering the facile synthesis and excellent Eu3+/Dy3+ doped luminescence properties of this compound, self-activated GdNbTiO6 may be a good candidate as a host phosphor for use in various optical devices.

Phase relations, crystal structures, and phase transformation of In1−xNb1−xTi2xO4 (0 ≤ x

Phase relations in the Cu–Ge–Ti ternary system have been studied through alloy sampling using electron probe microscopy (EPMA), and X-ray diffraction (XRD) techniques. A new ternary phase, τ 1 , was detected at 923 K. In light of the characterized phases in the annealed alloys, isothermal sections of the Cu–Ge–Ti system were constructed, which consist of 20 and 15 three-phase regions at 923 and 1073 K, respectively. In addition, the third element has limited solubility in binary compounds.

Novel CaInBO4: xEu(3+) phosphors were synthesized by solid-state reaction method. Their luminescent properties were characterized mainly by UV-visible PLE, PL, VUV, Decay lifetime, and TG-DTA. The excitation and emission spectra indicate that these phosphors can be effectively excited by ultraviolet about similar to 254 nm and exhibit red emission centered at similar to 613 nm attributed to D-5(0)-> F-7(2) transition of Eu3+. Optimum Eu3+ concentration of this phosphor is around 9 mol%. The effect of Al3+/Gd3+ and Ba2+/Sr2+ co-doped CaInBO4: Eu phosphor have been investigated, and the concentration dependence of the emission intensity shows that the optimum doping concentrations of Al3+ and Ba2+ are 3 mol% and 6 mol %, respectively. The UV-vis diffuse reflectance spectra indicate that these phosphors have wide transparent region and the incorporation of Al3+ ions and Ba2+ ions is in favor of light absorption for CIBO: Eu phosphor. The band gaps for these samples were obtained from diffuse reflection spectra, and the excitation wavelengths of phosphors were modified by adjusting their band gaps. According to their decay curves, the calculated lifetime of (Ca1-z, Ba/Sr-z) (In1-x-y, Al/Gd-y) BO4: xEu(3+) phosphors are all shorter than 2 ms. The chromaticity diagram shows that these phosphors can emit red light. The TG-DTA data presents that these phosphors have good thermal stability below 1100 degrees C. The present work suggests that these novel phosphors have potential applications for fluorescent lamps. (C) 2015 Elsevier B.V. All rights reserved.

Ce3+ doped CaAlSiN3 is a promising broadband orange phosphor that can be applied in white light-emitting diodes (wLEDs) solid state lighting for general illumination. However, its emission color and quantum efficiency are not good enough to achieve high color rendering properties and luminous efficacy of wLEDs. In this work, we proposed to realize the spectral tuning and property enhancement of CaAlSiN3:Ce3+ by bandgap engineering via the cationic substitution of Ca by Sr. The relationship between photoluminescence and local coordination structure as well as electronic structure were revealed. The substitution led to a blue-shift in emission maximum by 13 nm (from 595 to 582 nm) and a highest external quantum efficiency of 55% (enhanced by 10%). This broadband yellow phosphor enabled to produce wLEDs with a color rendering index of 83.3, luminous efficacy of 114.6 l m/W and a color temperature of 4604 K.

To develop the new luminescence materials, a series of Eu3+/Tb3+ doped novel KBaIn2(PO4)3 (KBIP) phosphors were successfully synthesized using the high-temperature solid-state method. The powder X-ray diffraction data and Rietveld refinement results showed that the phosphors are pure phases. The UV excited luminescence properties of the Eu3+/Tb3+ doped KBIP phosphors were investigated. Based on the UV spectra and decay curves, the efficient energy transfer from Tb3+ to Eu3+ in KBIP phosphor was recognized. In addition, the energy-transfer mechanism is ascribed to the resonant type via a non-radiative dipole-dipole interaction, with the transfer efficiency as high as 79.8%. At 150 °C, the overall emission intensity still maintains 68.5% of that at room temperature. The tunable color emission from green to red can be obtained by adjusting the concentration of doped Tb3+ and Eu3+ ions. The results indicate that the KBaIn2(PO4)3 based phosphors are potential candidate for applications in the plasma display panels (PDP) and lighting fields.

Based on diffusion triple and equilibrated alloy methods, phase relations in the Ti–Fe-Hf ternary system were investigated using the experimental data obtained through the combination of optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA) techniques. Isothermal sections of the Ti–Fe-Hf system at both 1073 K and 1273 K were well constructed. There are three and four three-phase regions in these two sections, respectively. According to the present results, Hf can dissolve into FeTi at approximately 3.0% at both 1073 K and 1273 K. A continuous solid solution of Fe2(Ti, Hf) forms between the binary intermediate compounds Fe2Ti and Fe2Hf (h). Fe2Hf(c) and FeHf2 show large solid solubilities. The solubility of Ti in Fe2Hf(c) changes from 33.9% at 1073 K to 39.0% at 1273 K, while that of FeHf2 can reach up to approximately 63.0% at 1273 K. No ternary compound exists in the Ti–Fe-Hf ternary system.

Color-tunable phosphors based on a single host are superior to traditional mixed primary-color phosphors in fluorescent lamps, due to the better consistency of different color components in service. In this work, a series of Eu3+/Tb3+ doped MgIn2P4O14 phosphors were synthesized by a conventional solid state reaction method. The phosphors exhibit strong absorption around 254 nm with negligible absorption in the visible light region. Under the joint action of the co-activation, cross-relaxation, sensitization, and phonon-assistance, color-tunable reddish-orange-yellow-green-blue emission is achieved in MgIn2P4O14: Eu, Tb phosphors by adjusting the doping content, which demonstrates great potential for the application in fluorescent lamps.

Cu-In-Te ternary chalcogenides have unique crystal and band structures; hence they have received much attention in thermoelectrics. In this work we have observed an enhancement in Hall carrier concentration (

Phase equilibria in the Cu–Ni–Zr ternary system have been measured through alloy sampling combined with diffusion couple approach. According to the phase relations identified with electron probe microanalysis and X-ray diffraction techniques, isothermal sections at both 1073 and 1293 K were constructed. It is evident that remarkable ternary solubility occurs in almost all binary intermetallic phases at both temperatures. The formerly reported ternary compounds T1 (Cu20–40Ni40–60Zr20) and T2 (Cu20–25Ni60–65Zr15) were not verified in this work. No other ternary compound was detected. In addition, continuous dissolution between Cu10Zr7 and Ni10Zr7 at 1073 K was observed.

By a sol–gel method, we obtained Ni 1− x Zn x O polycrystalline powders. The obtained Ni 1− x Zn x O was characterized by scanning electron microscope and transmission electron microscope techniques. The characterized results showed that the obtained Ni 1− x Zn x O showed hollow structure. The grain sizes of the obtained hollow Ni 1− x Zn x O were quite uniform, typically in the range of 400–500 nm. This method is a simple and effective method for large-scale synthesis of hollow Ni 1− x Zn x O quasi-spheres. The present method is very promising for large-scale production because the method is only involves commercial Zn(AC) 2 ·2H 2 O and NiCl 2 ·6H 2 O powders and the reaction is achieved in an open system free of autoclave and organic chemical reagents. This template-free method is facile but effective and therefore it is very promising for large-scale industrial production.

Subsolidus phase equilibrium of CoO–In 2 O 3 –B 2 O 3 system has been investigated mainly by solid-state reaction and powder X-ray diffraction method. A novel compound Co 2 InBO 5 was found and synthesized for the first time. There are five definite three-phase regions and one solid solution Co 3 − X In X BO 5 (0 X ⩽ 1) in this system under present experimental conditions. This new compound Co 2 InBO 5 and high temperature metastable phase Co 3 BO 5 can form continuous solid solution at all relative concentrations. Crystal structure of three representative Co 3− X In X BO 5 solid solution compounds ( X = 0.4, 0.7, and 1) were refined and determined from X-ray powder diffraction data using Rietveld method. The results showed that the Co 3− X In X BO 5 (0 X ⩽ 1) solid solution crystallized in the orthorhombic space group Pbam (No. 55) with the ludwigite structure type. The lattice parameters ( a , b and c ) of these solid solution compounds increase linearly when In replace Co atom gradually (i.e. with the increase of the value of X ), which obeys the Vegard’s rule. The trigonal BO 3 group in these Co 3− X In X BO 5 solid solution compounds was confirmed by their infrared absorption spectra.

Phase equilibria of Fe–Ti–Bi ternary system have been studied in this work. Firstly, by using alloy sampling, the isothermal section of Fe–Ti–Bi ternary system at 773 K was determined, where the existence of a ternary phase Bi 2 FeTi 4 was confirmed. Meanwhile, formation enthalpies of the intermediate phases BiTi 2 , Bi 9 Ti 8 and Bi 2 FeTi 4 , were obtained with first-principles calculations. Based on experimental data of phase equilibria and thermodynamic properties in literatures along with the calculated formation enthalpies in this work, thermodynamic modeling of Ti–Bi binary system and Fe–Ti–Bi ternary system were carried out with the CALPHAD approach. A set of self-consistent thermodynamic parameters to describe the Gibbs energy for various phases in Fe–Ti–Bi ternary system was finally obtained, with which solidification processes of two typical Fe–Ti–Bi alloys could be reasonably explained.

Phase equilibria in Al–Ti–Zr ternary system at 1273 K were experimentally investigated through alloy sampling combined with electron probe micro-analyzer (EPMA) and X-ray diffraction (XRD). No ternary compound was detected. Experimental results show that there is a continuous solid solution β(Ti, Zr) which dissolves up to 25.5 at.% Al, and Ti can substitute Zr in most Al–Zr binary intermediate phases to a certain degree while the maximum solubility of Zr in α 2 (Ti 3 Al) and γ(TiAl) reaches up to 25 at.% and 9 at.%, respectively. The isothermal section consists of 16 single-phase regions, 26 two-phase regions and 14 three-phase regions.

A novel ludwigite borate Mg 2 InBO 5 has been synthesized by solid-state reaction. Its crystal structure was solved by program Jana2006 from powder X-ray diffraction data, and then refined using Rietveld method. It crystallizes in the Pbam space group (No. 55) with a = 12.54806(8) A, b = 9.46943(6) A, c = 3.13855(2) A, V = 372.932(4) A 3 , and Z = 4. The disorder of Mg and In atoms exists in Mg 2 InBO 5 . The In atoms prefer to occupy the M1 and M2 site, while Mg atoms tend to occupy the M3 and M4 sites, which is in agreement well with the cation distributions in the ludwigite family. The crystal structure of Mg 2 InBO 5 is built from Mg/InO 6 octahedra and trigonal BO 3 groups stacking layer upon layer along the c -axis. The Mg/InO 6 octahedra connect each other by sharing edges to form two flat walls along the c -axis in the sequence M3–M2–M3 and M1–M4–M1. The trigonal BO 3 group in Mg 2 InBO 5 was confirmed by infrared absorption spectrum, and UV–Vis diffuse reflectance spectrum of Mg 2 InBO 5 has been measured. The structure characteristics of the ludwigite family were reviewed, with a possible rule proposed.

Two novel borate compounds MgInBO4 and MgIn7/8B7/8O29/(8), have been synthesized via solid-state reactions, and their crystal structures have been solved and refined from powder X-ray diffraction data. The compound MgInBO4, which was obtained at 1190 degrees C, belongs to the warwickite family. It crystallizes in the Pnma space group (no. 62) with a=9.5443(1) angstrom, b=3.2771(1) angstrom, c=9.5228(1) angstrom, and Z=4. The fundamental building units are liner -Mg(In)O-6-[In(Mg)](2)O-10-Mg(In)O-6- chains and isolated BO3 triangles. The low-temperature phase, MgIn7/8B7/8O29/8, whose crystal structure is solved ab initio by the charge-flipping method with standard chemical formula MgInBO4, was prepared at 1080 degrees C. It crystallizes in the P12(1)/n1 space group (no. 14) with a=17.0976(1) angstrom, b=3.2504(1) angstrom, c=5.3387(1) angstrom, beta=96.0829(3)degrees, and Z=4. The structure of MgIn7/8B7/8O29/8 contains[In(2)/Mg(2)](2)O-10 groups, -MgO6-InO6- infinite ribbons and isolated BO3 triangles. The experiments and the differential thermal analysis (DTA) show the decompositions of MgInBO4 and MgIn7/8B7/8O29/8 happen at about 1220 degrees C and 1180 degrees C, respectively. The comparative crystal chemistry from MgIn7/8B7/8O29/8 to MgInBO4 has been discussed. Infrared spectra and UV-vis diffuse reflectance spectra of MgInBO4 and MgIn7/8B7/8O29/8 were measured. (C) 2013 Elsevier Inc. All rights reserved.

Eu 3+ , Tb 3+ -doped Li 3 InB 2 O 6 (LIBO) phosphors were synthesized through conventional solid-state reaction. Their luminescence properties were studied for the first time. The excitation and emission spectra indicate that LIBO: Eu phosphor can be effectively excited by ultraviolet 394 nm and exhibit bright red emission centered at 613 nm attributed to 5 D 0 → 7 F 2 transition of Eu 3+ . Optimum Eu 3+ concentration of this phosphor is around 12%. LIBO: Tb phosphor exhibits green emission at about 543 nm excited by 377 nm light. There is neither emission from 5 D 3 level nor concentration quenching observed in this phosphor with Tb 3+ concentration from 2% to 14%. The corresponding luminescence mechanisms of Eu/Tb-doped LIBO phosphors were proposed. The decay curves and the calculated lifetime results of Eu/Tb-doped LIBO phosphors were obtained. The UV–vis diffuse reflectance spectrum indicates fundamental absorption edges of both pure and doped LIBO samples close to 320 nm. The present work suggests that the novel LIBO: Eu and LIBO: Tb phosphors are potential red and green phosphors for white light-emitting diodes.

Polycrystalline Sr3Sm2(BO3)4 borate has been synthesized through a solid-state reaction, and the title compound is stable in air and water. Its crystal structure was investigated from powder X-ray diffraction data using the Rietveld method. The fundamental building units of the crystal Sr3Sm2(BO3)4 are isolated BO3 anionic groups, distorted Sm–O polyhedra, and irregular Sr–O polyhedra, with the crystal structure isostructural to Sr3Nd2(BO3)4. The infrared spectrum of Sr3Sm2(BO3)4 has been measured, which is consistent with the crystallographic study. According to diffuse reflection measurement of Sr3Sm2(BO3)4 powders, the absorption edge is in the deep UV range and UV-vis transmittance is very high. Phosphor Sr3Sm2(BO3)4 exhibits an orange-red emission.

Subsolidus phase relations of CaO–In 2 O 3 –B 2 O 3 system have been investigated mainly by the conventional solid-state reaction technique and powder X-ray diffraction method. There are nine definite three-phase regions under present experimental conditions. Six binary compounds and one ternary compound were found to exist in this system. Crystal structure of the ternary compound CaInBO 4 was determined from X-ray powder diffraction data using Rietveld method. It crystallizes in the orthorhombic space group Pnma (No. 62) with a = 10.3120(3) A, b = 3.42519(8) A, c = 9.5150(3) A, V = 336.07(2) A 3 and Z = 4. Mixed occupancies were confirmed in this structure, Ca and In atoms are distributed between two atom sites: 93.6%Ca and 6.4%In occupy one site, 93.6%In and 6.4%Ca occupy another. Two In(Ca)O 6 octahedra and two Ca(In)O 7 polyhedra are linked each other by sharing edges to form ribbons in the a – c plane and extend infinitely along the direction of the b axis. The infrared spectrum of CaInBO 4 has been measured, which is consistent with the crystallographic study. In general, compounds MRBO 4 (M and R are divalent and trivalent cations, respectively) are in a large family of monoborates with different structure types strictly depending on the relative size of the M and R ions.

Arc melting of the elements followed by annealing (923 K, 10 d or 1073 K, 60 d) is used in combination with electron probe microscopy and powder XRD to evaluate the phase relations in isothermal sections of the Cu—Ge—Ti ternary system (20 and 15 three-phase regions at 923 and 1073 K, respectively).

Subsolidus phase equilibrium of BaO-In2O3-B2O3 system has been investigated mainly by solid-state reaction technique and powder X-ray diffraction method. There are 15 definite three-phase regions under present experimental conditions. Two ternary compounds, Ba3InB9O18 and Ba3InB3O9 were found and confirmed in this system. Crystal structure of Ba3InB3O9 was determined from X-ray powder diffraction data using Rietveld method. It crystallizes in space group R (3) over bar with six formula units of a cell with a = 12.7713(4)angstrom, c=9.3950(2)angstrom and V = 1327.09(8)angstrom(3). Coordination surrounding of B-O in this structure, [BO3](3-) group, was confirmed by infrared absorption spectrum of Ba3InB3O9. Ba3In1-xTbxB3O9 (x = 0.1-0.5) phosphors exhibited green emission at about 543 nm with 370 nm light excited. There is neither emission from D-5(3) level nor concentration quenching observed in the case of Ba3InB3O9:Tb3+, which can be explained from the crystal structural features of the matrix Ba3InB3O9. Chemical stabilization, simple preparation, and luminescence characteristics make phosphors Ba3InB3O9:Tb3+ have potential applications in white light-emitting diodes. (C) 2011 Elsevier B.V. All rights reserved.

The phase relations in the Al–Dy–Zr ternary system at 773 K have been investigated by X-ray powder diffraction (XRD) and scanning electron microscope (SEM) with energy disperse X-ray spectroscopy (EDX) in backscattered electron imaging (BSE) modes. The isothermal section at this temperature is featured with 17 single-phase regions, 32 two-phase regions and 16 three-phase regions. Besides, the ternary compound Al30Dy7Zr3 has been confirmed to be existed. The maximum solid solubility of Zr in AlDy2, Al2Dy3, AlDy, Al2Dy and Al3Dy at 773 K is determined to be 11.5 at.%, 7.8 at.%, 2.4 at.%, 22.5 at.% and 2.5 at.%, respectively.

Polycrystalline Li 3 Sc(BO 3 ) 2 was synthesized through the solid-state reaction, which is air-, water- and thermal-stable below about 929 °C. Its crystal structure was resolved and refined on the basis of powder X-ray diffraction data. The metal–borate framework is built up from ScO 6 octahedra connected to each other by sharing common edges, corners and faces of BO 3 units and LiO 4 groups. Coordination surrounding of B–O in this structure, [BO 3 ] 3− group, was confirmed by an infrared absorption spectrum of an Li 3 Sc(BO 3 ) 2 . According to the electronic structure calculated by first-principles calculations, an Li 3 Sc(BO 3 ) 2 is an insulator with a wide indirect energy band gap of about 4.4 eV. Considering the facile synthesis, large band gap, and thermal stability and excellent Tb 3+ -doped photoluminescence characteristics of this compound in general, it may be a good candidate as host of phosphors deposited on chip of the light-emitting diodes for white-color conversion.

KZnB3O6 is synthesized under ambient pressure from a stoichiometric mixture of K2CO3, ZnO, and H3BO3 (500 °C for 12 h and annealing at 750 °C for 24 h).

Borate Ba3InB9O18 (BIBO) has been adopted as a host material for phosphors for the first time. Lanthanide ions (Eu3+/Tb3+)-doped BIBO phosphors have been synthesized by solid-state reaction and luminescent properties investigated under ultravoilet (UV) excitation. For red phosphor BIBO:Eu, dominant emission peaking at 590 nm was attributed to D-5(0) -> F-7(1) transition of Eu3+, which confirmed that the local site of Eu3+ occupied by In3+ ion in BIBO crystal lattice is at inversion symmetry center. Optimum Eu3+ concentration of BIBO:Eu under UV excitation with 227 nm wavelength is around 40%. The green phosphor BIBO:Tb showed bright green emission at 550 with 232 nm light excited and optimal of Tb3+ concentration measured in BIBO is about 8%. The corresponding luminescence mechanisms of Ln-doped BIBO (Ln = Eu3+/Tb3+) were analyzed. The luminescent intensity of Tb3+ can be significantly improved by co-doping of Bi3+ in the BIBO:Tb lattice. The likely reason was proposed in terms of the different interactions of the host lattice with these ions, and of these ions with each other. (c) 2009 Elsevier B.V. All rights reserved.

Microstructure and phase equilibria of selected alloys of Hf–Si–B system have been studied in annealed conditions mainly by means of X-ray powder diffraction with aid of scanning electron microscope analysis. Compound Hf 5 Si 3 B 0.2 taking hexagonal structure (space group P 6 3 / mcm ), was confirmed with each unit cell containing two formulas and having lattice parameters a = 7.8557(1) A and c = 5.52622(1) A. Its crystal structure is made up of regular BHf 6 and HfSi 6 octahedra connected each other along direction by sharing common faces. This features a three-dimensional framework which is similar to that of analogue Mn 5 Si 3 structure. Besides, a thermodynamic description of Hf–Si–B system was developed based on its constituent binary systems and ternary experimental data from literatures and this work. Isothermal sections at 1273 K and 1573 K were calculated from our newly assessed thermodynamic description with comparison of experimental data.

Undoped and doped either by Eu{sup 3+} or Tb{sup 3+} bismuth borate Ba{sub 3}BiB{sub 9}O{sub 18} was structurally characterized and analyzed by fluorescence spectroscopy. Belonging to synthetic borate member of the family Ba{sub 3}XB{sub 9}O{sub 18}, layers of planar triangular B{sub 3}O{sub 6} groups connecting with deformed BaO{sub 6} hexagons are interleaved by 9-coordinate Ba atoms, and 6-coordinate Bi atoms. Its crystal structure was determined and refined from powder X-ray diffraction data by the Rietveld method and the results showed that Ba{sub 3}BiB{sub 9}O{sub 18} belongs to space group P6{sub 3}/m with unit cell dimensions of a = 7.1999(2) A, c = 17.3567(6) A, and z = 2. Curves of differential thermal analysis and thermogravimetric analysis showed that Ba{sub 3}BiB{sub 9}O{sub 18} is a congruent melting compound and chemically stable above 728 {sup o}C. Ba{sub 3}Bi{sub 1-x}Eu{sub x}B{sub 9}O{sub 18} and Ba{sub 3}Bi{sub 1-x}Tb{sub x}B{sub 9}O{sub 18} form a continuous solid solution from x = 0.01 to x = 0.9. The ultraviolet excited photoluminescence intensity increased with both Eu{sup 3+} and Tb{sup 3+} concentration in the matrix of Ba{sub 3}BiB{sub 9}O{sub 18}. There may be an interesting correlation between spectroscopic properties and lattice structural features of doped Ba{sub 3}BiB{sub 9}O{submore » 18}.« less

The subsolidus phase equilibria of the Li2O–Ta2O5–B2O3, K2O–Ta2O5–B2O3 and Li2O–WO3–B2O3 systems have been investigated mainly by means of the powder X-ray diffraction method. Two ternary compounds, KTaB2O6 and K3Ta3B2O12 were confirmed in the system K2O–Ta2O5–B2O3. Crystal structure of compound KTaB2O6 has been refined from X-ray powder diffraction data using the Rietveld method. The compound crystallizes in the orthorhombic, space group Pmn21 (No. 31), with lattice parameters a = 7.3253(4) A, b = 3.8402(2) A, c = 9.3040(5) A, z = 2 and Dcalc = 4.283 g/cm3. The powder second harmonic generation (SHG) coefficients of KTaB2O6 and K3Ta3B2O12 were five times and two times as large as that of KH2PO4 (KDP), respectively.

We report on the synthesis, crystal structure and scintillation property of a new compound Ba(3)InB(9)O(18). This compound crystallizes in space group P6(3)/m with unit cell of dimensions a = 7.1359(3) angstrom, c = 16.6151(8) angstrom and V = 732.697 angstrom(3) with two Ba(3)InB(9)O(18) molecular formula. Its crystal structure is made up of planar B(3)O(6) groups parallel to each other along the direction, regular InO(6) octahedra, irregular BaO(6) hexagons and BaO(9) polyhedra to form an analog structure of Ba(3)YB(9)O(18). DTA and TGA curves for Ba(3)InB(9)O(18) show that it is a chemically stable and congruent melting compound. Its X-ray excited luminescence spectra show an intense emission band in the range of 360-500 nm with a maximum at 400 nm. Light yield for Ba(3)InB(9)O(18) is about 75% as large as that for BGO under the same measurement conditions. There may exist a correlation between the scintillation properties and the crystal structural features of Ba(3)InB(9)O(18). (C) 2007 Elsevier Inc. All rights reserved.

New compounds Li6MB3O9(M=Nd,Sm,Eu,Tm,Er) were synthesized by solid-state reaction. The crystal structure of Li6NdB3O9was analyzed from both powder and single crystal X-ray diffraction data. The results obtained by powder diffraction analysis and Rietveld refinement area=7.2725(4) Å,b=16.6398(9) Å,c=6.7529(5) Å,β=105.398(8)°, and space groupP21/c, which agree with the results obtained by single crystal diffraction analysis:a=7.2712(4) Å,b=16.6268(9) Å,c=6.7484(4) Å,β=105.411(1)°, and space groupP21/c. This compound is isostructural with Li6YB3O9. Single crystal structure analysis showed that the fundamental building unit of these isostructural compounds comprises three isolated [BO3]3−triangles, one distorted [NdO8]13−triangulated dodecahedron, four distorted [LiO5]9−five-coordinated polyhedra, and two [LiO4]7−tetrahedron. An analysis of the infrared spectrum of Li6NdB3O9confirmed the presence of isolated [BO3]3−triangles in Li6NdB3O9. The remaining four Li6MB3O9(M=Nd, Sm, Eu, Tm, and Er) compounds were found to be isostructural with Li6NdB3O9. Their unit cell dimensions decrease with an increase in the atomic number of the rare-earth atoms. DTA and TGA measurements of Li6MB3O9(M=Nd, Sm, Eu, Tm, and Er) revealed that these borates congruently melt from 800 °C to 860 °C.