Birch Equation of State for Alkali Halide Crystals

Abstract

The Birch equation of state (BES) derived from the theory of finite strain is used to calculate the pressure versus volume compression data at room temperature for eleven alkali halide crystals, viz. LiF, LiCl, LiBr, LiI, NaF, NaC1, NaBr, NaI, CsC1, CsBr, and Csl. These crystals can be compressed to rather high pressures without appearance of any structural phase transformation. The parameters of BES are determined from the ultrasonically measured experimental values of the bulk modulus and its first pressure derivative and the calculated values of second pressure derivative of bulk modulus derived from interionic potential models. The resulting P-Vdata for all the crystals compare well with the corresponding experimental values reported by Vaidya and Kennedy and by Yagi.

Ab Initio Study of Structural and Electronic Properties of Sodium Bromide

“…Their results show that B 0 and B 0 are 199 kbar and 5.46, respectively. [16] Therefore, our result is almost the same as the experimental value of B 0 (195 kbar) and more accurate. The energy-band structure and (partial) densities of states are shown in Figs.…”

A comparative study of birch and kumar equations of state under high pressure NaCl as an example

“…The Birch EOS as used by Thomas and Shanker [13] depends on the determination of the second-order derivative of the bulk modulus. A critical analysis of such an approach has recently been presented by Kumar and Bedi [I41 pointing out that such EOSs, anyhow, are not better than that given by Murnaghan in 1944, for the pressure ranges considered by Thomas and Shanker [13].…”

THEORETICAL PREDICTION OF ELASTIC CONSTANTS FOR MgO

“…By using an exponential function for Ф, we get an EOS known as Born-Mayer EOS [1] which can be written as…”

“…Thermo elastic behavior of solids at high temperature gives the knowledge of temperature dependence of elastic modulii. In present work Various isothermal equations of state (EOS) such as the Born-Mayer EOS [1], Murnaghan EOS [2] and Birch EOS [3,4] …”