ELECTRICAL RESISTIVITY OF CUXZN1 - XFE2O4 SYSTEM.

THE VARIATION OF ELECTRICAL CONDUCTIVITY WITH COMPOSITION AND QUENCHING TEMPERATURE IN THE CU//XZN//1// - //XFE//2O//4 SYSTEM IS REPORTED. LOG OF RESISTIVITY ( ″RHO″ ) FOR CU//XZN//1// - //XFE//2O//4 QUENCHED SAMPLES DECREASES WITH INCREASING TEMPERATURE AND THIS PLOT CHANGES SLOPE, INDICATING CHANGE IN ACTIVATION ENERGY AT CURIE TRANSITION. THIS IS EXPLAINED ON THE BASIS OF COOPERATIVE BEHAVIOR OF POLARON. INCREASEOF ″RHO″ IS DUE TO IMPEDANCE OFFERED BY ZN**2** + IONS TO HOPPING WHILE THE DECREASE OF ″RHO″ MAY BE DUE TO MAGNETIC ORDERING CHANGE. ON QUENCHING, ″RHO″ OF THE SAMPLES DECREASES AS USUAL EXCEPT FOR CU//0//. //2ZN//0//. //8FE//2O//4 AND ZNFE//2O//4. IN THESE TWO SAMPLES ENERGY FOR HOPPING IS INDEPENDENT OF QUENCHING TEMPERATURE.