scholarly journals Effect of Thermal Stresses Formed during Air Annealing of Amorphous Lanthanum Cuprate Thin Films Deposited on Silicon Substrate

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 613 ◽  
Author(s):  
Nolwenn Tranvouez ◽  
Philippe Steyer ◽  
Annie Malchère ◽  
Pascal Boulet ◽  
Fabien Capon ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Thermal Stresses ◽  
Environmental Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lift Off

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.

Thermal expansion coefficient of carbon-supported Pt nanoparticles: In-situ X-ray diffraction study

2017 ◽  
Vol 254 (5) ◽  
pp. 1600695 ◽  
Author(s):  
I. N. Leontyev ◽  
A. A. Kulbakov ◽  
M. Allix ◽  
A. Rakhmatullin ◽  
A. B. Kuriganova ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Diffraction Study ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Pt Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray

Graphite thermal expansion coefficient measured by in-situ x-ray diffraction

2020 ◽  
Vol 31 (28) ◽  
pp. 285709
Author(s):  
Monis Abdulmanan Abdullah ◽  
Thar Mohammed Badri Albarody ◽  
Alaa Raad Hussein
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
X Ray Diffraction ◽  
X Ray

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
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Structural and Thermal Unusual Properties in Invar Behavior of Ni-Mn Alloys

2020 ◽  
Vol 17 (2(SI)) ◽  
pp. 0629
Author(s):  
Salih Darweesh et al.
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Lattice Distortion ◽  
Negative Thermal Expansion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Metals ◽  
Invar Effect

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.    

Phase transition and thermal expansion coefficient of leucite ceramics with addition of SiO2

2009 ◽  
Vol 24 (6) ◽  
pp. 1989-1993 ◽  
Author(s):  
Juan Paulo Wiff ◽  
Yoshiaki Kinemuchi ◽  
Shimako Naito ◽  
Ayako Uozumi ◽  
Koji Watari
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Intermediate Phase ◽  
Linear Thermal Expansion ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After

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.

Preparation and Anisotropic Lattice Thermal Expansion of Hexagonal Cordierite

2017 ◽  
Vol 726 ◽  
pp. 470-477
Author(s):  
Jin Hua Zhang ◽  
Chang Ming Ke ◽  
Hong Dan Wu ◽  
Ji Shun Yu
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Least Squares Method ◽  
Rietveld Method ◽  
X Ray Diffraction ◽  
Lattice Thermal Expansion ◽  
Thermal Expansion Behavior ◽  
X Ray ◽  
Expansion Behavior

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.

Temperature-driven directional coalescence of silver nanoparticles

2016 ◽  
Vol 23 (3) ◽  
pp. 718-728 ◽  
Author(s):  
Shi Yan ◽  
Dongbai Sun ◽  
Yu Gong ◽  
Yuanyuan Tan ◽  
Xueqing Xing ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Silver Nanoparticles ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Temperature Dependent ◽  
X Ray ◽  
Nanoparticle Growth

Silver nanoparticles were synthesized with a chemical reduction method in the presence of polyvinylpyrrolidone as stabilizing agent. The thermal stability behavior of the silver nanoparticles was studied in the temperature range from 25 to 700°C. Thermal gravimetric analysis was used to measure the weight loss of the silver nanoparticles. Scanning electron microscopy and high-resolution transmission electron microscopy were used to observe the morphology and the change in shape of the silver nanoparticles.In situtemperature-dependent small-angle X-ray scattering was used to detect the increase in particle size with temperature.In situtemperature-dependent X-ray diffraction was used to characterize the increase in nanocrystal size and the thermal expansion coefficient. The results demonstrate that sequential slow and fast Ostward ripening are the main methods of nanoparticle growth at lower temperatures (<500°C), whereas successive random and directional coalescences are the main methods of nanoparticle growth at higher temperatures (>500°C). A four-stage model can be used to describe the whole sintering process. The thermal expansion coefficient (2.8 × 10−5 K−1) of silver nanoparticles is about 30% larger than that of bulk silver. To our knowledge, the temperature-driven directional coalescence of silver nanocrystals is reported for the first time. Two possible mechanisms of directional coalescence have been proposed. This study is of importance not only in terms of its fundamental academic interest but also in terms of the thermal stability of silver nanoparticles.

Anomalous Thermal Expansion and Spontaneous Magnetostriction of Gd2Fe16.5Cr0.5 Compound

2012 ◽  
Vol 580 ◽  
pp. 544-547
Author(s):  
Chun Jing Gao ◽  
Yan Ming Hao ◽  
Fei Fei Liang ◽  
Huai Gu Hu
Keyword(s):  
Magnetic Properties ◽  
Thermal Expansion ◽  
Curie Temperature ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Magnetic State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spontaneous Magnetostriction ◽  
Anomalous Thermal Expansion

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.

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