CONDUCTIVITY RELAXATION PARAMETERS OF SOME H+ AND K+ CONDUCTING IN THE POLYCRYSTALLINE COMPOUND KDYP3O10

Polycrystalline samples of KDyHP3O10 was obtained by heating for 12 ho ur at 553 K a mixture containing K2CO3, Dy2O3 and H3PO4. Samples were characterized through X-ray diffraction, examined by IR vibrational sp ectroscopy and impedance and modulus spectroscopy techniques. The cond uctivity relaxation parameters of some H+ and K+ conducting in this co mpound have been determined from an analysis of ac conductivity data m easured in a wide temperature range. Transport properties in this mate rial appears as due to H+ and K+ ions hopping mechanism. The stretched exponential function exp[-(t/tau(sigma))(beta)] has been used to desc ribe the conductivity relaxation. The relaxation parameters have been investigated as a function of the nature of mobile ions. The results o btained are shown to be in good agreement with the predictions of the Ngai coupling model. (C) 1998 Elsevier Science B.V. All rights reserve d.