scholarly journals The Polythermal Section of Ti-22Al-xNb (30-78at.%Ti) in Ti–Al–Nb System

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 871
Author(s):  
Yun Zhao ◽  
Li-Bin Liu ◽  
Li-Gang Zhang ◽  
Jia-Jun Yang ◽  
Patrick J. Masset
Keyword(s):  
Single Phase ◽  
Invariant Reaction ◽  
Polythermal Section ◽  
Electron Probe Micro Analysis ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Three Phase ◽  
Micro Analysis ◽  
O Phase

The polythermal section of Ti-22Al-xNb (30–78 at.% Ti) in the Ti-Al-Nb system was studied using X-ray diffraction analysis (XRD), differential thermal analysis (DSC), and electron probe micro-analysis (EPMA). No new ternary compounds were found in this work. The polythermal section has five three-phase regions, nine two-phase regions, and three single-phase regions. The O phase transition is confirmed to occur below 1000 °C. A four-phase invariant reaction β + σ → O + δ was found at 931 °C.

Phase Relationships in the Y–Fe–V Ternary System at 773 K

2011 ◽  
Vol 704-705 ◽  
pp. 475-479
Author(s):  
Shun Kang Pan ◽  
Rui Yan ◽  
Huai Ying Zhou ◽  
Li Chun Cheng ◽  
Qing Rong Yao ◽  
...  
Keyword(s):  
Ternary System ◽  
Single Phase ◽  
Maximum Solid Solubility ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Energy Dispersion Spectroscopy ◽  
X Ray ◽  
Three Phase ◽  
Scanning Electron ◽  
Phase Relationships

The isothermal section of the phase diagram of the ternary system Y–Fe–V at 773 K was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS) techniques. It consists of 9 single-phase regions, 16 two-phase regions and 8 three-phase regions. The ternary compound YFe12-xVx (1.5≤x≤2.7, space group I4/mmm) with Mn12Th-type structure was confirmed in this system. At 773 K, the maximum solid solubility of V in Fe, and YFe2, is about 23 at.%, and 3 at.%, respectively, Fe in V is about 22 at.%. And that of Y in Fe, FeV and V don′t exceed 1 at.%.

scholarly journals Термодинамические свойства оксипентафторида ванадия (IV), (NH-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-VOF-=SUB=-5-=/SUB=-

2020 ◽  
Vol 62 (7) ◽  
pp. 1123
Author(s):  
Е.В. Богданов ◽  
Е.И. Погорельцев ◽  
А.В. Карташев ◽  
М.В. Горев ◽  
М.С. Молокеев ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Single Phase ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Limits Of Stability ◽  
Three Phase ◽  
Temperature Dependences ◽  
Spectroscopy Studies

Abstract The (NH_4)_3VOF_5 crystals have been synthesized and their homogeneity and single-phase structure has been established by the X-ray diffraction, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy studies. The investigations of the temperature dependences of specific heat, entropy, strain, and pressure susceptibility show the occurrence of three phase transitions caused by the structural transformations in the (NH_4)_3VOF_5 crystals. The T – p phase diagram shows the temperature limits of stability of the crystalline phases implemented in (NH_4)_3VOF_5. The optical and dielectric studies disclose the ferroelastic nature of the phase transitions. An analysis of the experimental data together with the data on the isostructural (NH_4)_3VO_2F_4 crystal makes it possible to distinguish the physical properties of oxyfluorides containing vanadium of different valences (IV and V).

SYNTHESIS, CHARACTERIZATION, AND SELF-CONTROLLED ORTHORHOMBIC TO TETRAGONAL POLYMORPHIC TRANSFORMATION IN BaTiO3 NANOPARTICLES

2007 ◽  
Vol 21 (25) ◽  
pp. 1697-1714
Author(s):  
S. RAM ◽  
A. JANA ◽  
T. K. KUNDU
Keyword(s):  
Composite Structure ◽  
Single Phase ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Volume ◽  
Proposed Model ◽  
Diffraction Peaks ◽  
Two Phases ◽  
O Phase

The phase formation and thermal-induced phase transformation are studied in BaTiO 3 nanoparticles. 2 h of heating a polymer precursor at 550°C in air formed a single phase BaTiO 3 of 15 nm average crystallite size D. The X-ray diffraction peaks are analyzed assuming a P nma orthorhombic (o) crystal structure of lattice parameters a = 0.6435 nm , b = 0.5306 nm , and c = 0.8854 nm . The lattice volume V = 0.3023 nm 3, with z = 4 formula units, yields a density ρ = 5.124 g/cm 3. This is a new polymorph in comparison to well-known P m3m tetragonal (t) structure, V = 0.0644 nm 3 or ρ = 6.016 g/cm 3 (z = 1). An o ↦ t transformation appears on heating at temperature as high as 650°C in air. A proposed model explains the transformation above a certain D value in terms of the Gibbs free energy. Unless heating above 750°C, the two phases coexist in a composite structure (D≤27 nm ), with as much residual o-phase trace as ~28 vol%. As a function of temperature both the phases decrease in the V values up to 0.2975 and 0.0643 nm3 at 750°C respectively (0.0650 nm3 at 650°C). This is an important parameter for designing useful ferroelectric and other properties in a hybrid composite structure.

Phase relationships in the Ce–Nd–B system at 773 K

2020 ◽  
Vol 111 (6) ◽  
pp. 526-532
Author(s):  
Xuehong Cui ◽  
Jinming Zhu ◽  
Ketong Luo ◽  
Jianlie Liang
Keyword(s):  
Solid Solution ◽  
Ternary System ◽  
Continuous Solid Solution ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Three Phase ◽  
Phase Relationships

Abstract Phase relationships in the Ce-Nd-B ternary system at 773 K were investigated by means of X-ray diffraction and scanning electron microscopy with energy dispersive X-ray spectroscopy techniques. Six borides, i. e. CeB4, CeB6, NdB4, NdB6, NdB66 and Nd2B5 are confirmed in this work. No ternary compound was observed. CeB4 and NdB4 were discovered to form the continuous solid solution phase (Ce,Nd)B4, CeB6 and NdB6 also form the solid solution phase (Ce,Nd)B6. The maximum solid solubility of Ce in (Ce,Nd)2B5 phase is 46.5 at.%. The isothermal section of the Ce-Nd-B ternary system at 773 K consists of 3 three-phase regions, 7 two-phase regions and 7 single- phase regions.

scholarly journals Experimental Study on the Phase Relations of the SiO2-MgO-TiO2 System in Air at 1500°C

JOM ◽  
2021 ◽  
Author(s):  
Min Chen ◽  
Xingbang Wan ◽  
Junjie Shi ◽  
Pekka Taskinen ◽  
Ari Jokilaakso
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Phase Relations ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Phase Domain ◽  
Isothermal Equilibration ◽  
Isothermal Phase Diagram ◽  
Three Phase ◽  
Measured Liquid

AbstractWe investigated the phase relations of the SiO2-MgO-TiO2 system in air at 1500°C using the high-temperature isothermal equilibration/quenching technique, followed by x-ray diffraction measurements and direct phase analysis using scanning electron microscopy coupled with x-ray energy dispersive spectrometry. One single liquid phase domain, five two-phase domains (liquid-TiO2, liquid-cristobalite, liquid-MgO·SiO2, liquid-2MgO·SiO2, and liquid-MgO·2TiO2), and five three-phase regions (liquid-TiO2-MgO·2TiO2, liquid-MgO·SiO2-cristobalite, liquid-TiO2-cristobalite, liquid-MgO·SiO2-2MgO·SiO2 and liquid-2MgO·SiO2-MgO·2TiO2) were observed. We constructed a 1500°C isothermal phase diagram based on the experimentally measured liquid compositions. We compared simulations using MTDATA and FactSage thermodynamic software and their databases with the experimental results obtained in this study. These results can be used to provide guidelines for updating the MTDATA and FactSage titania-bearing thermodynamic databases by reassessing the thermodynamic properties of the phase with new experimental data.

120 K SUPERCONDUCTOR TlBaCaCu2Oy

1988 ◽  
Vol 02 (01) ◽  
pp. 479-481 ◽  
Author(s):  
Z.X. ZHAO ◽  
L.Q. CHEN ◽  
Z.H. MAI ◽  
Y.Z. HUANG ◽  
Z.L. XIAO ◽  
...  
Keyword(s):  
Single Phase ◽  
Oxide System ◽  
Tetragonal Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Edax Analysis ◽  
Micro Analysis ◽  
Single Phase Material

We have prepared 120 K superconductor in Tl-Ba-Ca-Cu oxide system. This 120 K superconductor has been investigated by x-ray diffraction and EDAX micro-analysis. EDAX analysis shows that the composition of this superconductor is very close to TlBa ( Ca 1−x Cu x) CuO y(x−0.3). Most of the x-ray powder diffractions including all the strong ones can be indexed according to a tetragonal structure with a=5.46 Å and c= 36.2 Å which means that the sample is nearly a single phase material.

Synthesis and Characterization of Ti-TiB Composites Processed through Vacuum Sintering

2014 ◽  
Vol 592-594 ◽  
pp. 765-769
Author(s):  
M. Selva Kumar ◽  
P. Chandrasekar ◽  
Balasubramanian Ravisankar ◽  
M. Mohanraj
Keyword(s):  
Volume Fraction ◽  
Titanium Boride ◽  
Electron Probe Micro Analysis ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Increase With Increase ◽  
Micro Analysis

In the present work, an attempt has been made to explore the general microstructural characteristics and mechanical properties of titanium-titanium boride (Ti-TiB) composites (20 and 40 vol.% TiB reinforcement in Ti matrix) processed by Vacuum Sintering. The microstructures of the composites were investigated using electron probe micro analysis, scanning electron microscopy and X-ray diffraction. Obviously, the elastic modulus, shear modulus and hardness are found to increase with increase in volume fraction of titanium boride. The effects of titanium boride reinforcements on elastic properties and microhardness are discussed.

X-ray diffraction study of the effect of boron on lattice properties of Ni76Al24

1993 ◽  
Vol 8 (4) ◽  
pp. 741-744 ◽  
Author(s):  
Mohan P.V. Rao ◽  
Murthy K. Satyanarayana ◽  
S.V. Suryanarayana ◽  
Naidu S.V. Nagender
Keyword(s):  
Diffraction Study ◽  
Single Phase ◽  
Lattice Parameter ◽  
Small Addition ◽  
X Ray Diffraction ◽  
Fault Probability ◽  
Two Phase ◽  
X Ray ◽  
Al Content ◽  
Stacking Fault Probability

A small addition of boron is suggested to increase the ductility of the polycrystalline Ni3Al when the Al content is less than 25 at.%. Both metallographic and x-ray investigation have shown the alloys of Ni3Al (24 at.% Al) containing 0.20, 0.42, 0.79, 0.98, and 1.22 at.% B to be of single phase and that of 1.76 at.% B to be of two phase. With the addition of boron, the lattice parameter of the Ni3Al phase is found to increase. Microhardness measurements indicate that initially the hardness decreases for the alloy of 0.20 at.% B, while for the rest of the single phase alloys the hardness is found to increase with further addition of boron. The addition of boron increases the deformation stacking fault probability value except for the alloy with 0.20 at.% B.

Crystal Chemistry of Zemannite-Type Structures: III. Keystoneite, the Ni2+-Analogue of Zemannite, and Ferrotellurite Discredited

2021 ◽  
Author(s):  
Owen P. Missen ◽  
Malcolm E. Back ◽  
Stuart J. Mills ◽  
Andrew C. Roberts ◽  
Yvon LePage ◽  
...  
Keyword(s):  
Full Description ◽  
Electron Probe Micro Analysis ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Boulder County ◽  
Micro Analysis ◽  
Historical Samples ◽  
The Ideal

ABSTRACT Keystoneite (IMA87–049) is a tellurite mineral from the Keystone mine, Magnolia District, Boulder County, Colorado, USA. In this paper the first full description of keystoneite is presented. Keystoneite is the Ni2+ analogue of zemannite and has the ideal zemannite-like formula of Mg0.5Ni2+Fe3+(Te4+O3)3·4H2O. The chemical composition via electron-probe micro-analysis (in wt.%; standard deviations in brackets) is Na2O 0.3 (0.2), K2O 0.1 (0.0), MgO 4.3 (0.3), Mn2O3 1.1 (0.7), Fe2O3 5.1 (1.2), NiO 12.7 (1.7), and TeO2 65.5 (0.7). H2O was determined by TGA analysis, giving 15(3) wt.% H2O, however, H2O from the structural determination gave 10.0 wt.%, the latter giving an analytical total of 99.1 wt.%. Keystoneite crystallizes in the non-centrosymmetric space group P63. The six strongest observed powder-diffraction lines [d,Å(I)(hkl)] are 8.12(90)(100), 4.05(80)(200), 2.952(50)(112), 2.838(50)(121,211), 2.774(100)(202), and 1.720(60)(204). The unit-cell parameters determined from single-crystal X-ray diffraction are a = 9.3667(5) Å, c = 7.6173(3) Å, V = 578.77(6) Å3, and Z = 2. Keystoneite was first identified from a specimen of “ferrotellurite”, a mineral with the reported formula Fe2+Te6+O4. The discreditation of “ferrotellurite” has been accepted by the IMA-CNMNC, Proposal 19-G, as no material corresponding to a phase remotely similar to Fe2+Te6+O4 was found on any historical samples labelled as containing “ferrotellurite”.

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