High Temperature Guinier X-Ray Diffractometry for Thermal Expansion Measurements in the Hexagonal Form of Cordierite (2MgO·2A12O3·5SiO2)

1984 ◽  
pp. 397-404 ◽  
Author(s):  
J. S. Pressnall ◽  
J. J. Fitzpatrick ◽  
Paul Predecki
1983 ◽  
Vol 27 ◽  
pp. 397-404
Author(s):  
J. S. Pressnall ◽  
J. J. Fitzpatrick ◽  
Paul Predecki

AbstractA computer-controlled high temperature Guinier diffractometer system for accurate determination of lattice thermal expansion is described. A critical test of the system using α-Al2O3 (0.3μ polishing alumina) showed close agreement with the single crystal expansion data of Wachtman et al. Lattice thermal expansion of cordierite doped with the following dopants: Ge+4, P+5, Zn+2, Li+1 and Ca+2 was investigated. Of these the Li+1 at the 5% level (5% of Si+4 replaced by Li+1 + Al+3) produced the largest decrease in mean lattice expansion.


1959 ◽  
Vol 13 ◽  
pp. 1767-1774 ◽  
Author(s):  
Arne Kjekshus ◽  
Fredrik Grønvold ◽  
Peer Møller Jørgensen ◽  
Susanne Refn

1990 ◽  
Vol 5 (1) ◽  
pp. 183-189 ◽  
Author(s):  
H. M. O'Bryan ◽  
P. K. Gallagher ◽  
G. W. Berkstresser ◽  
C. D. Brandle

Dilatometry, high-temperature x-ray diffraction, differential thermal analysis, and differential scanning calorirmetry have been performed on LaGaO3, NdGaO3, PrGaO3, SmAlO3, and LaAlO3 single crystals grown by the Czochralski technique. First order phase transitions have been located at 145°C for LaGaO3 and 785°C for SmAlO3, and ΔH has been measured for the LaGaO3 transition. Second order transitions have been identified for LaGaO3, PrGaO3, NdGaO3, and LaAlO3. The usefulness of these compounds as substrates for high temperature superconducting films is discussed in terms of thermal expansion matching.


2018 ◽  
Vol 20 (5) ◽  
pp. 3847-3850
Author(s):  
S. I. Sadovnikov ◽  
A. I. Gusev ◽  
A. V. Chukin ◽  
A. A. Rempel

Correction for ‘High-temperature X-ray diffraction and thermal expansion of nanocrystalline and coarse-crystalline acanthite α-Ag2S and argentite β-Ag2S’ by S. I. Sadovnikov et al., Phys. Chem. Chem. Phys., 2016, 18, 4617–4626.


1986 ◽  
Vol 30 ◽  
pp. 503-510
Author(s):  
H.A. McKinstry ◽  
Lai Daik Chai ◽  
R.V. Sara ◽  
K.E. Spear

Thermal expansion is an interesting, ubiquitous and neglected property of materials. Recently, Lenain et al. (1985) and Limaye (1986) have been investigating anisotropy in the low-expansion structures of the sodium zirconium phosphate family. In the hexagonal structure one axis expands while another contracts. In going from the calcium to the strontium analog the anisotropy actually changes sign. A change in anisotropy between CrB2 and TiB2 had been observed by R.V. Sara (1960). The results in Fig. 1 obtained by high temperature x-ray diffraction measurements indicate that for TiB2 the thermal expansion of the c-axis is greater than the expansion of the a-axis, whereas for CrB2 the reverse is true.


1961 ◽  
Vol 5 ◽  
pp. 191-212 ◽  
Author(s):  
H.J. Goldschmidt

AbstractHigh-temperature X-ray powder photography has proved of great value in many directions in the metallurgical field. Some of the successes achieved and problems encountered by the author and other investigators using an established-type camera (British Unicam) for temperatures up to 1400°C will be discussed. This will be by way of specific case histories, chosen both for their own scientific interest and to illustrate the techniques employed. The applications concern phase transformations and the measurement of coefficients of thermal expansion in iron and steels, as well as in some nonferrous metals and inorganic compounds.


2019 ◽  
Vol 33 (23) ◽  
pp. 1950271 ◽  
Author(s):  
Y. I. Aliyev ◽  
Y. G. Asadov ◽  
A. O. Dashdemirov ◽  
R. D. Aliyeva ◽  
T. G. Naghiyev ◽  
...  

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.


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