Hydrostatic Pressure Effect on the Dielectric Properties of K₂SeO₄

Hydrostatic pressure effect on the dielectric constant ε_c or K₂SeO₄ was studied. The incommensurate transition temperature T₂ lowers linearly with the slope of –7.3±0.2 K/kbar. The Curie temperature T₃ also decreases with pressure, but the slope denpends on pressure; the initial slope is –17.2±2.5 K/kbar and the slope above 0.6 kbar is –11.4±1.0 K/kbar. The dielectric behaviors under the pressure are qualitatively discussed based on the theoretical treatments already developed by other authors, and some problems are suggested.