FACTORS AFFECTING THE SINTERING AND THE ELECTRICAL-PROPERTIES OF SR-DOPED LACRO3

Sr-doped samples of lanthanum chromite have been synthesized by additi on (LaSr(x)CrO3) and by substitution (La1-xSr(x)CrO3) up to x = 0.2. T he influence of sintering temperatures up to 1600-degrees-C, of sinter ing time, of atmosphere and of particle size on the densification and on the electrical conductivity of both series was investigated. High r elative densities (0.95) and high electrical conductivities (>1 OMEGA- 1 cm-1) can be obtained at T < 1600-degrees-C and in oxidizing atmosph ere provided that: (i) x > 0.1, (ii) the La+Sr/Cr ratio is greater tha n 1, (iii) the LaCrO3 particles are submicronic. Emphasis is placed on the effect of alumina introduced in the samples by vibratory milling. The subsequent alteration of the electrical properties in the La1-xSr (x)CrO3 samples is explained on the basis f of a careful microanalysis of the chromite and secondary phases by SEM and EDAX.