TEMPERATURE DEPENDENCE OF THE THERMAL EXPANSION COEFFICIENT, BULK MODULUS AND MAGNETIC GRUENEISEN CONSTANT OF NICKEL NEAR THE CURIE POINT

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-65-C8-66 ◽  
Author(s):  
T. Faisst
1998 ◽  
Vol 54 (6) ◽  
pp. 741-749 ◽  
Author(s):  
M. Catti ◽  
A. Pavese

A two-body interatomic potential function, including fractional atomic charges and a shell model for oxygen, and supplemented by an O—Al—O bond-angle energy term, was fitted to the structural, elastic and vibrational properties of \alpha-Al2O3, corundum, at ambient conditions. Full quasi-harmonic calculations were then carried out on a p,T grid of 54 points in the domain 0–40 GPa and 300–1700 K. The crystal structure was equilibrated at each point, taking into account the anisotropy of vibrational pressure and the thermal dependence of elastic constants, so as to obtain unit-cell edges, atomic coordinates, bulk modulus, thermal expansion coefficient and other thermodynamic properties. Polynomial approximations were developed to represent the p,T dependence of these quantities. Comparison with experimental results for the separate p (T = 300 K) and T (p = 0) behaviours shows very good agreement, with average deviations of 0.1% for the unit-cell volume and 6% for the thermal expansion coefficient. The coupled p,T dependence of the properties of corundum is predicted to be very small for the bulk modulus (\partial^2K_T/\partial p\partial T=8.4\times10^{-5} K−1), but not at all negligible for the volume [(1/V)\partial^2V/\partial p\partial T in the range −1.2 to −7.5 × 10−7 GPa−1 K−1 over the p,T domain explored].


2013 ◽  
Vol 27 (25) ◽  
pp. 1350180 ◽  
Author(s):  
RAGHUVESH KUMAR ◽  
GEETA SHARMA ◽  
MUNISH KUMAR

A simple theoretical model is developed to study the effect of size and temperature on the coefficient of thermal expansion and lattice parameter of nanomaterials. We have studied the size dependence of thermal expansion coefficient of Pb , Ag and Zn in different shape viz. spherical, nanowire and nanofilm. A good agreement between theory and available experimental data confirmed the model predictions. We have used these results to study the temperature dependence of lattice parameter for different size and also included the results of bulk materials. The temperature dependence of lattice parameter of Zn nanowire and Ag nanowire are found to present a good agreement with the experimental data. We have also computed the temperature and size dependence of lattice parameter of Se and Pb for different shape viz. spherical, nanowire and nanofilm. The results are discussed in the light of recent research on nanomaterials.


1971 ◽  
Vol 35 (5) ◽  
pp. 377-378 ◽  
Author(s):  
J. Major ◽  
F. Mezei ◽  
E. Nagy ◽  
E. Sváb ◽  
G. Tichy

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