ROLE OF PARTICLE-SIZE AND MOLE PERCENT OF THE DISPERSOID IN COMPOSITESOLID-ELECTROLYTE SYSTEM SR(NO3)2-AL2O3

The role played by the particle size and mol% of alumina particles whe n dispersed in strontium nitrate system was studied in the range of te mperatures from about 100-degrees-C to 560-degrees-C. Enhancement of c onductivity was noticed to increase with mol% (m/o) of the dispersoid in the extrinsic temperature region. For a given m/o the enhancement w as noticed to increase with decrease of particle size. Different parti cle sizes namely 36.9, 0.3, and 0.06 mum were used with varying mol%. The maximum enhancement observed was between 10(2)-10(3) times with re spect to the host material. Analysis of the results clearly indicated the dependence of enhancement on the total surface area of the dispers oid available for a given volume of the host material. The enhancement increased with total surface area upto a limit, started decreasing wi th further increase in the total surface area and finally dropped to a value below that for the pure material. This phenomenon is explained on the basis of formation of space charge layers between the host ioni c conductor and the insulating particles.