Using Variable Temperature Powder X-ray Diffraction To Determine the Thermal Expansion Coefficient of Solid MgO

2007 ◽  
Vol 84 (5) ◽  
pp. 818 ◽  
Author(s):  
Nicholas C. Corsepius ◽  
Thomas C. DeVore ◽  
Barbara A. Reisner ◽  
Deborah L. Warnaar
2020 ◽  
Vol 17 (2(SI)) ◽  
pp. 0629
Author(s):  
Salih Darweesh et al.

The Invar effect in 3D transition metal such as Ni and Mn, were prepared on a series composition of binary Ni1-xMnx system with x=0.3, 0.5, 0.8 by using powder metallurgy technique. In this work, the characterization of structural and thermal properties have been investigated experimentally by X-ray diffraction, thermal expansion coefficient and vibrating sample magnetometer (VSM) techniques. The results show that anonymously negative thermal expansion coefficient are changeable in the structure. The results were explained due to the instability relation between magnetic spins with lattice distortion on some of ferromagnetic metals.    


2017 ◽  
Vol 254 (5) ◽  
pp. 1600695 ◽  
Author(s):  
I. N. Leontyev ◽  
A. A. Kulbakov ◽  
M. Allix ◽  
A. Rakhmatullin ◽  
A. B. Kuriganova ◽  
...  

2009 ◽  
Vol 24 (6) ◽  
pp. 1989-1993 ◽  
Author(s):  
Juan Paulo Wiff ◽  
Yoshiaki Kinemuchi ◽  
Shimako Naito ◽  
Ayako Uozumi ◽  
Koji Watari

In this work, the influence of SiO2 additions in leucite ceramics on the bulk linear thermal expansion coefficient (TEC) especially during the phase transition, has been studied. Thermal expansion and x-ray diffraction measurements at high temperatures were carried out to characterize the tetragonal-cubic phase transition. TEC for reference and SiO2-added leucite samples exhibited similar behavior as a function of temperature. Before and after the phase transition, the TEC values were similar to those observed in non-SiO2-added samples, whereas during the phase transition, a maximum TEC value was observed and it tends to decrease as the SiO2 addition increases. This behavior could be caused by the formation of an intermediate phase with an extremely high TEC (70 × 10–6 °C−1) during the phase transformation. Furthermore, the results suggest that as the intermediate phase is partially suppressed via SiO2 addition, the cubic phase can be partially stabilized at temperatures as low as 200 °C.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 613 ◽  
Author(s):  
Nolwenn Tranvouez ◽  
Philippe Steyer ◽  
Annie Malchère ◽  
Pascal Boulet ◽  
Fabien Capon ◽  
...  

Amorphous thin films of La–Cu–O deposited by magnetron sputtering have been annealed at different temperatures and in situ analyzed by X-ray diffraction. These experiments were useful to determine the crystallization temperature and to follow the crystallization process of the film. The in situ annealing X-ray diffraction analyses have been also used to determine the thermal expansion coefficient of La2CuO4 thin film. The estimated value is close to that obtained for a commercial powder. The thermal expansion coefficient value with additional environmental scanning electron microscopy observations explains the delamination origin that occurs during the annealing before the crystallization step. The buckling and delamination of the film observed is caused by the thermal expansion coefficient mismatch of the film and the substrate. During the heating step, the mismatch generates compressive stress at the film/substrate interface, causing the film to lift off and crack in the typical way.


2017 ◽  
Vol 726 ◽  
pp. 470-477
Author(s):  
Jin Hua Zhang ◽  
Chang Ming Ke ◽  
Hong Dan Wu ◽  
Ji Shun Yu

The hexagonal cordierite was synthesized by the reverse coprecipitation-calcination method and characterized by powder X-ray diffraction. The lattice thermal expansion behavior of hexagonal cordierite was investigated by high temperature X-ray diffraction in the temperature range 298-1273 K. The lattice parameters of the hexagonal cordierite at different temperature were calculated by a least squares method. The hexagonal cordierite expressed anisotropic thermal expansion behavior with the average lattice thermal expansion coefficient were 2.13×10-6 K-1 along a or b axis and-1.03×10-6 K-1 along c axis from room temperature to 1273 K. The crystal structure of hexagonal cordierite at 298 K and 1273 K were refined by Rietveld method. The thermal expansion coefficient of the height of the [MgO6]-[AlO4] polyhedral layer is-1.8×10-6 K-1. Although the six-member ring expressed the normal positive thermal expansion along arbitrary direction, the height thermal expansion coefficient of the six-member ring is just 0.6×10-6 K-1.


2012 ◽  
Vol 580 ◽  
pp. 544-547
Author(s):  
Chun Jing Gao ◽  
Yan Ming Hao ◽  
Fei Fei Liang ◽  
Huai Gu Hu

The thermal expansion and magnetic properties of Gd2Fe16.5Cr0.5compound have been investigated by means of X-ray diffraction and magnetization measurements. The Gd2Fe16.5Cr0.5compound has a rhombohedral Th2Zn17-type structure. The Curie temperature of Gd2Fe16.5Cr0.5compound is about 560K. This value is about 50K higher than that value of the mother compound Gd2Fe17. A small average thermal expansion coefficient, = 1.65×10-6/K, and a negative average thermal expansion coefficient, = -1.46×10-5/K, were found in Gd2Fe16.5Cr0.5compound by X-ray diffraction in the temperature range 294 - 514K, and 514-613K, respectively. There exists anisotropic strong spontaneous magnetostriction in the magnetic state of Gd2Fe16.5Cr0.5compound.


2015 ◽  
Vol 816 ◽  
pp. 271-276
Author(s):  
Xiao Ge Chen ◽  
Yuan Wei ◽  
Xian Ping Zhang ◽  
Hong Song Zhang

(Sm1-xNdx)2Ce2O7ceramics was synthesized by solid reaction method at 1873K for 10h in the present investigation. The density, phase structure, thermal conductivity and thermal expansion coefficient of (Sm1-xNdx)2Ce2O7ceramics were studied by the Archimedes method, X-ray diffraction (XRD), laser-flash and pushing rod. The (Sm1-xNdx)2Ce2O7ceramics have pure fluorite-structure. The thermal conductivity of (Sm1-xNdx)2Ce2O7ceramics decreased with an increase of Nd2O3content at identical temperature conditions, and the thermal expansion coefficient increased with increasing Nd-doping content. The synthesized (Sm1-xNdx)2Ce2O7ceramics can be explored as an ideal candidate material for future thermal barrier coatings.


2000 ◽  
Vol 15 (6) ◽  
pp. 1349-1353 ◽  
Author(s):  
D. Sriram ◽  
R. L. Snyder ◽  
V. R. W. Amarakoon

Barium hexaferrite is a well-known ceramic permanent magnet and due to its high coercivity, remanence, and large uniaxial magnetic anisotropy, finds applications that compete with metallic magnets. Even though a number of the high-temperature properties of barium hexaferrite have been studied extensively, its anisotropic thermal expansion has not been reported so far. Dynamic high-temperature x-ray diffraction (HT-XRD) is one powerful method to obtain thermal expansion data for anisotropic polycrystalline materials in a very short period of time. In this paper the anisotropic nature of the thermal expansion coefficient of the barium hexaferrite phase is reported with the use of a dynamic HT-XRD setup. The thermal expansion coefficient (linear fit) was determined to be 8.36 × 10−6 K−1 along the a–b plane to 1.4 × 10−5 K−1 along the c axis between the temperature range of 293 to 1343 K.


2020 ◽  
Vol 31 (28) ◽  
pp. 285709
Author(s):  
Monis Abdulmanan Abdullah ◽  
Thar Mohammed Badri Albarody ◽  
Alaa Raad Hussein

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