Ferromagnetism in Nanocrystalline SrCo0.9Mn0.1O3-δ: a Structural, Magnetic and Electrical Transport Study.

The physical properties of the nanocrystalline SrCo0.9Mn0.1O3-δ sample prepared by citrate-gel method have been investigated. The sample crystallizes in rhombohedral crystal symmetry with space group R32/155. Temperature dependence of zero field cooled (ZFC) and field cooled (FC) magnetization exhibit paramagnetic to ferromagnetic (PM-FM) transition at 164 K. The high temperature and low temperature synthesized phases show different magnetic ground state. The deviations in magnetization data around magnetic ordering temperature are also studied using the Langevin function. This attributed to the presence of intrinsic superparamagnetic (SPM) nanocluster contribution. Temperature dependence of average cluster moment is calculated and found to be maxima near transition temperature. The temperature dependence electrical resistivity of the samples shows semiconducting-like behavior for the studied range of temperature. The conduction mechanism of the samples has been analyzed using Mott's variable range hopping model to calculate the density of states in the vicinity of Fermi energy (N (EF)) and hopping distance (Rh). All electrical parameters vary systematically and are in good agreement with other reported semiconducting oxides. [ABSTRACT FROM AUTHOR]