Structural phase transition, ionic conductivity, and dielectric investigations in K3H(SO4)2 single crystals

Pretransition Phenomena in Fast-Proton Conductors

“…3. In accordance with Chen et al [12] the KHS conductivity at about 360 K is of an order of 10 −5 Ω −1 cm −1 . An external dc field above about 4 kV/cm leads to nonlinearity in the linewidth behavior strictly connected with the current flow.…”

Dielectric and AC Conductivity οf Potassium Perchlorate, KCLO4

“…where N(E f ) is the density of states at Fermi level, υ ph is the phonon frequency in the order of 10 13 sec −1 and α is the decay of the localized states wave function (α ≈ 1 Å) [16]. The expression that describes the behavior of s, in the QMT model is given by: s = 1 − {4/ ln(υ ph /ω)} (7) whereas, for classical hopping:…”

“…The above equation is called the power law or universal dynamic response and is used to analyze the conductivity in all disordered solids [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. In this equation A(T ) and s(T ) are characteristic parameters which are temperature dependent.…”

“…Of particular interest, is the frequency exponent whose value lies in the range 0 < s < 1. The exponent measures the degree of interaction of mobile ions with the environment [16]. A(T ) determines the polarizability [29].…”

Nonlinear effects in fast-proton conductors studied by EPR and bulk methods

“…The KHS crystal has a specific structure which contains a "zero-dimensional" hydrogen-bond network consisting of isolated SO~--H-9 9 SO4 zdimers. Below 471 K, KHS exhibits ferroelastic properties, and above 471 K, it reveals high protonic conductivity of the order of 10 -I ~-lcm-I [4,5].…”