Hydrostatic Pressure Dependence of T_C for SASD Type Crystals

Abstract

Some consequences of the modified two sublattice model being an extension of the Mitsui model [1] are discussed in connection with recently obtained experimental data on hydrostatic pressure dependence of T _c for SASD type crystals. It is shown that both the sign of the dT _c /dp and nonlinearyty of the T _c (p) function can be predicted from the proposed model assuming that some parameters describing the interactions between active groups depend linearly on hydrostatic pressure p. The so-called pressure factor α is estimated to be in the limits from 3 × 10⁻⁴ MPa⁻¹ to 12 × 10⁻⁴ MPa⁻¹.

Keywords:

• Sodium ammonium dihydrate
• EPR
• hydrostatic pressure
• phase transitions

PACS numbers:

• 76.30.K
• 77.80.Bh.