Effect of the phonon and magnetic anharmonicity on the thermal and elastic properties of nearly magnetic δ-plutonium

Electron heat capacity and lattice properties of Americium

“…The electron part of the thermodynamic potential [11] can be written in the form (2) where l = f, d is the band index; U (l) is the parameter of the Hubbard repulsion of electrons of the l band; (ε) is the density of states of the l band, calculated in accordance with the LDA + U + SO scheme (in the full potential linearized augmented plane wave (FP LAPW) method); μ is the chemical potential of elec trons determined from the electroneutrality condition…”

“…(3) in the energy units (i.e., is multiplied by the Boltzmann constant in electronvolts, which is equal to 0.8625 × 10 -4 eV/K); 2n l is the filling factor of the l band; and = is the mean square of the modulus of the random onsite exchange field (see [10,11]). The contribution to the TDP associated with para magnons and their interaction has the form (3) where…”

A thermodynamic model of thermal end elastic properties of curium

“…One can see that Debye temperature of Cm is essentially lower than Debye temperature of Gd, which according to [8] is of about 170 K. The bulk modulus of Cm rather weakly depends on temperature as compared with e.g. Np [6] and d-Pu [7], which indicates that Cm can be characterized by relatively weak phonon anharmonicity. This fact is confirmed by the calculated contribution of phonon anharmonicity to the heat capacity of Cm and by the values of…”

“…Following [6][7][8] we consider the connection of Debye temperature h with molar volume V and bulk modulus B in the form…”

“…In the present study a simulation of temperature dependences of the thermal and elastic properties of Cm is carried out in terms of the self-consistent thermodynamic model [6][7][8], which along with the lattice properties accounts for the effect of electronic subsystem.…”