Abstract:
The equation of state, as well as the baric and temperature dependences of the thermoelastic and surface properties of monocrystalline tantalum, were calculated using an analytical method (i.e., without computer simulation). This method is based on the paired interatomic four-parameter Mie-Lennard-Jones potential and takes into account the contributions of both the lattice and electronic subsystems of the metal. Using this method, the baric and temperature dependences of the isothermal elastic modulus, thermal expansion coefficient, isobaric heat capacity, and derivatives of these functions with respect to pressure were calculated. The baric dependences are calculated along the isotherms $T$ = 300 and 3000 K, and the temperature dependences are calculated along the isobars $P$ = 0 and 100 GPa. It is shown that the calculated dependencies are in good agreement with the dependencies obtained both experimentally and using computer simulating. For the first time, the surface properties of tantalum have been calculated: the specific surface energy, as well as its derivatives in temperature and pressure. The tantalum properties have been studied under $P$–$T$ conditions which hard-to-reach for the experiment, and it was found out in which $P$–$T$ arguments the electronic contribution to these properties is noticeable, and in which area its influence on the tantalum properties can be neglected.
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