Thermoelastic Properties of Superoxide

Abstract

We have applied an Extended Three Body Force Shell Model (ETSM) by incorporating the effect of translational- rotational coupling for the investigation of thermoelastic properties such as cohesive energy(??, molecular force constant(f), compressibility(b), Restrahlen frequency (?_?), Debye temperature (q_D), Gruneisen parameter (g), second Gruneisen parameter (q), Moelwyn Hughes constants (F₁), and ratio of volume expansion coefficient (a_v) to volume specific heat (c_v ) of superoxide materials NaO₂ and KO₂ at 300K. Besides this we have calculated static shear modulii (c₄₄). The shear modulii computed between the temperatures ranges 50K to 500K. Here, we could compare our result with experimental data for thermal properties only at room temperature and the magnitudes of SOECs seem to be correct, also the ETSM method produces the sign of SOECs correctly.

Keywords: Orientationally Disordered Materials, Shear modulii, ETSM, TR coupling, Elastic constants]

PACS: 62.60.bc,; 65.50-f