In this paper, an isothermal three-parameter equation of state (EOS) of solid is proposed in the form V/V0 = f(P), with pressure P as the independent and relative volume V/V0 as the dependent variable. The proposed EOS uses three parameters expressible in terms of B0, B′0 and B″0, denoting bulk modulus and its first and second pressure derivatives at zero pressure. The new model is applied to the isotherms of ionic, metallic, quantum and rare-gas solid, with pressures ranging from zero to variable maximum pressures of up to 1 TPa. The fits are uniformly excellent. Root-mean-square deviations between data and fits are computed and compared with the three-parameter empirical EOS proposed by Kumari and Dass [J. Phys.: Condens. Matter 2, 3219 (1990)]. It is shown that our new form yields a decisively superior fit. Furthermore, it is shown that our proposed equation of state has an advantage for some close-packed materials because it allows B′∞ = (δBs/δP)s (P → ∞) to be fitted, and this is where the usual standard equations fail badly.
|Original language||English (US)|
|Number of pages||8|
|Journal||Physica Status Solidi (B) Basic Research|
|State||Published - Jul 2001|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics