Electrical conductivity and phase transition studies on K2SO4 crystals

Conductivity and dielectric relaxation phenomena in (NH4)2SO4 single crystal

“…The obtained activation energy of (NH 4 ) 2 SO 4 is also comparable to those of isomorphous K 2 SO 4 crystal, for which the values around 1.10 eV were obtained by Chen et al [18], Choi et al [29], and Diosa et al [30]. The K + was proposed to have the contribution to the electrical conductivity for K 2 SO 4 crystal [18,29,30]. It is then proposed that the ammonium ion in (NH 4 ) 2 SO 4 single crystal may have the contribution to the electrical conduction.…”

Coupled anion and cation dynamics of silver orthophosphate in the picosecond range

“…Similar behaviour was reported in other substances, e.g., LiNaSO 4 [2,3], LiAgSO 4 [4], K 2 SO 4 [5], Li 4 Zn(SO 4 ) 3 [6], CsHSO 4 [7], K 2 CrO 4 [8] and Na 3 PO 4 [9].…”

The solid state phase transformation of potassium sulfate

“…Other authors observed the α−β transformation of K 2 SO 4 at 592 • C or 612 • C, respectively [6,7], but these investigations were performed with mixtures instead of pure K 2 SO 4 . Electrical conductivity measurements on single crystals have been carried out by Choi et al [8], the transition temperature range extends to 3 K and transition occurs at 586.9 • C on heating and 581.5 • C on cooling, with a thermal hysteresis of 5.4 K. Chen et al performed electrical complex impedance measurements on K 2 SO 4 single crystals [9]. The T dependence of electrical conductivity and dielectric constant revealed an anomaly around 587 • C which was attributed to the transformation to α-K 2 SO 4 .…”