Electrical conduction behaviour of cobalt substituted BaSnO3

A few cobalt substituted barium stannate, BaSn1-xCoxO3 compositions have be en synthesized by solid state ceramic method. Seebeck coefficient alpha has been measured as a function of temperature. Positive values of 'alpha' ind icate that holes are the majority charge carriers. AC conductivity, sigma ( ac) has been measured in the temperature range 310-550 K and frequency rang e 100 Hz to 10c MHz. The contributions of the grains and grainboundaries to the total conductivity have been obtained by complex plane impedance analy sis. Complex plane impedance analysis shows that conduction occurs by hoppi ng of charge carriers among localized sites. (C) 2001 Kluwer Academic Publi shers.