ANALYSIS OF ELECTRIC RELAXATION IN SODIUM TRISILICATE AND LITHIUM FLUOROBORATE GLASSES FROM 10(2) TO 10(9) HZ AND 25 TO 300-DEGREES-C

It was found that subtraction of effects of an assumed 'Warburg' surface impedance, z = z1(i-omega)-a, from measured parallel capacitance and conductance yields constant low frequency values with relaxation of both at higher frequencies. After subtraction of dc conductance, the remaining complex, epsilon*, is described quite well by the Cole-Davidson (CD) relaxation function with beta approximately 0.36 plus excess absorption at the highest frequencies. The high frequency conductivity approaches the linear variation with omega proposed by Wong and Angell. It can also be joined smoothly to extrapolated far IR reflectivity measurements of damped cation motion resonances (unpublished results of Burns and Risen). The following unified interpretation is proposed: cation vibrations in local potential minima are precursors of occasional escapes to adjacent sites and ensuring diffusive charge displacements and transport which is ultimately blocked by space charge accumulations near electrodes.