Polymorphic transformations and thermal expansion of some modifications in Ag1.5Cu0.5Se and Ag0.4Cu1.6Se

2019 ◽  
Vol 33 (23) ◽  
pp. 1950271 ◽  
Author(s):  
Y. I. Aliyev ◽  
Y. G. Asadov ◽  
A. O. Dashdemirov ◽  
R. D. Aliyeva ◽  
T. G. Naghiyev ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Polymorphic Transformations ◽  
X Ray

The Ag[Formula: see text]Cu[Formula: see text]Se and Ag[Formula: see text]Cu[Formula: see text]Se compounds have been synthesized and grown as single crystals. High-temperature X-ray diffraction method was used to study polymorphic transformations. It is shown that the Ag[Formula: see text]Cu[Formula: see text]Se crystals of high-temperature FCC modification are decomposed into Ag2Se and AgCuSe when the temperature decreases below T = 488 K and Ag[Formula: see text]Cu[Formula: see text]Se is decomposed into Cu2Se and AgCuSe when the temperature decreases below T = 540 K. Transformations in both compounds are reversible. Crystalline parameters are obtained and the temperature dependence of the lattice parameters for each phase is built.

Thermal Expansion of Cu-Ga-Sn Alloys

2014 ◽  
Vol 353 ◽  
pp. 137-142
Author(s):  
V.A. Bykov ◽  
T.V. Kulikova ◽  
K.Yu. Shunyaev ◽  
A.B. Shubin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Expansion ◽  
Temperature Dependence ◽  
Linear Thermal Expansion ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Tin Alloys ◽  
X Ray ◽  
Scanning Electron

The thermal and microstructural properties of five copper-gallium-tin alloys (Cu-Ga-Sn) and two important intermetallic compounds Cu3Sn and CuGa2 have been investigated by dilatometry, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. The temperature dependence of thermal expansion and coefficient of linear thermal expansion (CLTE) were obtained.

Thermal Expansion of Alloys from the Al-Fe System

2012 ◽  
Vol 326-328 ◽  
pp. 587-592 ◽  
Author(s):  
Anna Śmiglewicz ◽  
Magdalena Jabłońska
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermal Expansion Coefficient ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Analysis Method ◽  
Standard Methods ◽  
Casting Technique ◽  
Thermal Analyzer ◽  
Alloys Of The Al

In this work, the results of a dilatometric study of alloys on the base of the Al-Fe system were presented. Thermal expansion investigations of the alloys of the Al-Fe system with concentration of Al equal to - 38, 48, 58 at.% were also presented. The alloys were obtained by classical casting technique. The thermal expansion studies of the alloys were carried out by dilatometric analysis method using a Setsys thermal analyzer made by Setaram. A linear thermal expansion coefficient α was calculated using standard methods. A temperature dependence of the α coefficient was noted. The results are an important supplement of knowledge on the alloys of the Al-Fe system.

scholarly journals Studies on Thermophysical Properties of CaO and MgO by γ-Ray Attenuation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Madhusudhan Rao ◽  
K. Narender
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermophysical Properties ◽  
Linear Thermal Expansion ◽  
Temperature Dependent ◽  
Degree Polynomial ◽  
Attenuation Coefficients ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

The study on temperature dependent γ-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300 K–1250 K using different energies of γ-beam, namely, Am (0.0595 MeV), Cs (0.66 MeV), and Co (1.173 MeV and 1.332 MeV) on γ-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (μl) for the pellets of CaO and MgO as a function of temperature have been determined using γ-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300 K–1250 K has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported.

MAGNETO-ELASTIC PROPERTIES OF MnZnSb

1993 ◽  
Vol 07 (01n03) ◽  
pp. 895-898
Author(s):  
S. MORI ◽  
T. KANOMATA ◽  
H. YAMAUCHI ◽  
H. YOSHIDA ◽  
T. KANEKO
Keyword(s):  
Field Theory ◽  
Thermal Expansion ◽  
Curie Temperature ◽  
Temperature Dependence ◽  
Elastic Properties ◽  
Pressure Effect ◽  
Phenomenological Theory ◽  
Lattice Parameters ◽  
Molecular Field ◽  
Negative Exchange

The temperature dependence of the magnetization ,σ, the pressure effect on the Curie temperature, TC, and the thermal expansion for MnZnSb are measured. The value of dTC/dp is +3.6 K/kbar. Negative exchange strictions are observed for the lattice parameters a and c. The results are discussed using a phenomenological theory based on the molecular field theory.

scholarly journals Thermoresponsive studies of porous and non-porous borophosphates.

2014 ◽  
Vol 70 (a1) ◽  
pp. C504-C504
Author(s):  
Mashikoane Mogodi ◽  
David Billing
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Hexagonal Lattice ◽  
Linear Thermal Expansion ◽  
Lattice Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Group I ◽  
Lattice Space ◽  
Helical Channels

In this work we present the synthesis and structure-property investigation of anhydrous low porosity borophsophates [1] BPO4 and porous (NH4)0.5M1.25(H2O)2)(BP2O8)(H2O)0.5 M = Co (II), Mn (II) and NH4Fe[BP2O8(OH)] phases. Cristobalite-type BPO4 crystallizes in the tetragonal lattice, space group I-4 (No. 82) [2]. Variable-Temperature Powder X-ray diffraction (VT-PXRD) patterns for these material were analysed by the sequential and parametric Rietveld refinement [3] protocols. Both methods were used to determine the temperature dependency of the lattice parameters and linear thermal expansion coefficient. Whereas the lattice parameters were refined freely in the sequential method, the individual cell parameters were described using an empirically derived function in the parametric method. Both refinement protocols reveal significant anisotropy along the a- and c- axis as a function of temperature, with thermal expansion coefficients of 10.6 x10-6 /0C and 2.83 x10-6 /0C, respectively. Structural changes accompanying this thermoresponsive behaviour will be discussed, including the variation of the interatomic distances and P-O-B (inter-polyhedral angle, figure 1) with temperature. The open framework (NH4)0.5M1.25(H2O)2)(BP2O8)(H2O)0.5 M = Co(II) (1a), Mn(II) (1b) and NH4Fe[BP2O8(OH)] (2) phases were synthesized under mild hydrothermal methods at 1800C. The crystal structure of the isostructural (1a) and (1b) phases were refined in the hexagonal lattice, space group P65 (no. 170) and compound (2) in the monoclinic lattice, space group P21/c (no.14). Both (1a) and (1b) phases consists of NH4+ and H2O molecules located within the helical channels running along the [001] direction with compound (2) consisting exclusively of NH4+ molecules located within the helical channels running along the [100] direction. Thermoresponsive investigation conducted by TGA analysis reveal a five, four and three step mass loss process for compounds (1a), (1b) and (2) respectively, with the final step observed at 500-7000C range. Preliminary VT-PXRD results of these compounds will also be presented.

An X-ray determination of the thermal expansion of α-phase Cu–Si alloys at high temperature

1989 ◽  
Vol 22 (4) ◽  
pp. 380-381
Author(s):  
S. K. Pradhan ◽  
M. De
Keyword(s):  
Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Solute Concentration ◽  
Lattice Parameters ◽  
Thermal Expansion Coefficients ◽  
Solid Solution Range ◽  
Expansion Coefficients ◽  
Increasing Temperature ◽  
Room Temperature Increase

Lattice parameters for four Cu–Si alloys containing 2.2, 4.3, 6.4 and 8.7 at.% Si in the solid-solution range have been calculated in the temperature range 303–928 K. The lattice parameters increase slowly in a nonlinear manner with rise in temperature. The calculated linear thermal-expansion coefficients (α) at room temperature increase with increasing solute concentration (Si) but decrease almost linearly with increasing temperature, the rate of decrease being higher for alloys with higher solute concentration. All the alloys have almost the same average α value (α av ~ 16.0 × 10−6 K−1), which is the value of α at the temperature interval 615–625 K for all the alloy compositions.

Thermal expansion of decagonal Al70.7Co13.3Ni16.0 in the temperature range 15–300 K

2001 ◽  
Vol 216 (12) ◽  
Author(s):  
A. Kupsch ◽  
D. C. Meyer ◽  
P. Gille ◽  
P. Paufler
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Lattice Parameters ◽  
Temperature Range

AbstractThe temperature dependence of lattice parameters

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