Thermal expansion and high-temperature phase transformation of the yttrium silicate Y2SiO5

2001 ◽  
Vol 16 (8) ◽  
pp. 2251-2255 ◽  
Author(s):  
J. W. Nowok ◽  
J. P. Kay ◽  
R. J. Kulas
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Linear Thermal Expansion ◽  
Anomalous Behavior ◽  
High Temperature Phase ◽  
Local Order ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yttrium Silicate

The linear thermal-expansion coefficients of yttrium silicate Y2SiO5, [Y2(SiO4)O] were measured in the temperature range from 20 to 1400 °C using x-ray diffraction. The anomalous behavior of thermal expansion was observed above Tc = 850 °C and was attributed to the displacive phase transformation. The transformation was reversible and resulted from the local order °C the compositional disorder and local fluctuation in the elastic free energy constrained a secondary transformation related to the polymorphic twin transformation. This created an additional peak in x-ray diffraction patterns at 2 's intensity. The characteristic of phase transformation both on heating and on cooling of the sample was also investigated using the differential thermal analysis method. The thermogravimetric technique did not indicate on a change of weight at Tc.

scholarly journals High-temperature phase transition of SrRuO3and SrHfO5: X-ray diffraction and PAC spectroscopy

1996 ◽  
Vol 52 (a1) ◽  
pp. C364-C364
Author(s):  
J. A. Guevara ◽  
S. L. Cuffini ◽  
Y. P. Mascarenhas ◽  
P. de la Presa ◽  
A. Ayala ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Pac Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Phase Transition

scholarly journals Study of the High Temperature Phase of 1,16-Hexadecanediol by Polarized Light Microscopy and Glancing Incidence X-Ray Diffraction

2018 ◽  
Vol 24 (S1) ◽  
pp. 2248-2249
Author(s):  
M. Ramírez-Cardona ◽  
M.P. Falcón-León ◽  
G. Luis-Raya ◽  
G. Mejía-Hernández ◽  
R. Arceo ◽  
...  
Keyword(s):  
High Temperature ◽  
Light Microscopy ◽  
Polarized Light ◽  
High Temperature Phase ◽  
Polarized Light Microscopy ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray

From six- to five-coordinated SbIII in [(CH3)3PH]3[Sb2Cl9]: transition pathways from single-crystal X-ray diffraction

2008 ◽  
Vol 64 (5) ◽  
pp. 558-566 ◽  
Author(s):  
Anna Gagor ◽  
Maciej Wojtaś ◽  
Adam Pietraszko ◽  
Ryszard Jakubas
Keyword(s):  
Phase Transitions ◽  
Phase I ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Octahedral Environment ◽  
Transition Pathways ◽  
Cl Atoms ◽  
Unusual Increase

[(CH3)3PH]3[Sb2Cl9] experiences four phase transitions which were found by means of calorimetry, thermogravimetry and X-ray diffraction. The crystal structure was solved in the space group P63/mmc at 382 K (phase I), Pnam at 295 K (phase II) and Pna21 at 175 K (phase V). We observed an unusual increase in symmetry from the monoclinic to the orthorhombic form at the IV\rightarrowV transition. The parent hexagonal high-temperature phase I consists of highly disordered [(CH3)3PH]+ cations and [Sb2Cl9]3− anions with an octahedral environment of SbIII. The transition from phases I to II is associated with the ordering of [(CH3)3PH]+ cations. Moreover, the successive transformations from phases I to V are related to the change in the arrangement of Cl atoms in [Sb2Cl9]3− anions from the discrete `face-sharing bioctahedra' (phase I) to two corner-sharing square pyramids. A mechanism for the phase transitions is proposed. It is observed that weak C—H...Cl interactions are responsible for the structure arrangement in low-temperature phases.

Investigation on the Thermal Stability of the Compounds Y3Fe29-xCrx

2013 ◽  
Vol 820 ◽  
pp. 71-74
Author(s):  
Xiao Hua Wang ◽  
Wei He ◽  
Ling Min Zeng
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Single Phase ◽  
Binary Compound ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Transition Elements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

Binary compound Y3Fe29cannot be directly formed by rare earth Y and Fe and the third element M (non-iron transition elements) must be introduced to form ternary compound Y3(Fe,M)29. In this work, six alloys with compositions of the Y3Fe29-xCrx(x=1,2,3,4,5,6) were prepared and investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and differential thermal analysis (DTA). The study on the thermal stability of these compounds points to that the compoundY3(Fe,Cr)29is a high temperature phase and exists above 1100K. The alloys with single-phase of Y3(Fe,Cr)29was decomposed into Y2(Fe,Cr)17and Y(Fe,Cr)12annealed at high temperature 1100K.

In Situ Time-Resolved X-Ray Diffraction Investigation of the ω→ψ Transition in Al-Cu-Fe Quasicrystal-Forming Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 943-947 ◽  
Author(s):  
E. Otterstein ◽  
R. Nicula ◽  
J. Bednarčík ◽  
M. Stir ◽  
E. Burkel
Keyword(s):  
Large Scale ◽  
Applied Pressure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Xrd ◽  
Kinetics Of

Quasicrystals are aperiodic long-range ordered solids with a high potential for many modern applications. Interest is nowadays paid to the development of economically viable large-scale synthesis procedures of quasicrystalline materials involving solid-state transformations. The kinetics of the high-temperature phase transition from the complex ω-phase to the icosahedral quasicrystalline (iQC) ψ-phase in AlCuFe nanopowders was here examined by in-situ time-resolved X-ray diffraction experiments using synchrotron radiation. In-situ XRD experiments will allow insight on the influence of uniaxial applied pressure on the kinetics of phase transitions leading to the formation of single-phase QC nanopowders and further contribute to the optimization of sintering procedures for nano-quasicrystalline AlCuFe alloy powders.

Behaviors of the Zr–1.0Sn–0.39Nb–0.31Fe–0.05Cr Alloy at High Temperature

2011 ◽  
Vol 399-401 ◽  
pp. 80-84
Author(s):  
Yi Yuan Tang ◽  
Jie Li Meng ◽  
Kai Lian Huang ◽  
Jian Lie Liang
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
High Temperature ◽  
Oxide Film ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thin Oxide Film ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

Phase transformation of the Zr-1.0Sn-0.39Nb-0.31Fe-0.05Cr alloy was investigated by high temperature X-ray diffraction (XRD). The XRD results revealed that the alloy contained two precipitates at room temperature, namely β-Nb and hexagonal Zr(Nb,Fe,Cr,)2. β-Nb was suggested to dissolve into the α-Zr matrix at the 580oC. Thin oxide film formed at the alloy’s surface was identified as mixture of the monoclinic Zr0.93O2and tetragonal ZrO2, when the temperature reached to 750oC and 850 oC. The thermal expansion coefficients of αZr in this alloy was of αa = 8.39×10-6/°C, αc = 2.48×10-6/°C.

Sign in / Sign up

Export Citation Format

Share Document