Rietveld Refinement of Cobalt Doped Magnesium Aluminate Spinel Nanoparticles

Abstract

Among various transition metals, Co: MgAl₂O₄ can be regarded as a good one for applications like high mechanical resistance, high chemical and thermal stability, and low temperature sinterability of spinel type oxide materials. The physical properties like chemical strength, catalytic ability, and high temperature resistivity of cobalt doped magnesium aluminate have been further enhanced. Cobalt-magnesium aluminate crystallizes at relatively higher temperature, i.e. above 850°C as compared to un-doped magnesium aluminate that crystallizes around 800°C. A single phase cobalt doped magnesium aluminate fcc ordered-spinel nanopowder (grain size ~ 20 nm) with a good, chemical homogeneity, is obtained by using co-precipitation method followed by thermal treatment at temperature 1000°C for 4h, in air. Rietveld refinement is performed by FULLPROF program and used to confirm the results of XRD of samples calcined at 850^oC and 1000^oC (4h).