Room temperature ferromagnetism in chemically synthesized dilute magnetic semiconducting (In 0.95 Mn 0.05 ) 2 O 3 nanoparticles

Single-phase nanocrystalline In 2 O 3 doped with 5 atomic percent Mn produces dilute magnetic semiconductor (DMS). The material is synthesized by low temperature ‘pyrophoric reaction’ using nitrate salts and diethanolamine. The XRD pattern at room temperature reveals the formation of cubic bixbyite structure of the oxide with nano-structured grain which is confirmed by FESEM. Magnetization data confirms ferromagnetic behavior at room temperature with gradual decrease in magnetization with rise of temperature. The phase transition occurred at 500 K is attributed to the transformation of ferromagnetic to paramagnetic state of the nanometric sample. Curie–Weiss inverse magnetic susceptibility [ χ −1 ( T )] plot against temperature deduced the effective Bohr magneton ( μ eff ) to be ~ 3.65 μ B /Mn ion. Ferromagnetism may have generated from mixed valence states (Mn 4+ major /Mn 3+ minor) of Mn which is 3d element. Valence state was determined by chemical method using redox reaction between Fe 2+ and Mn 4+ / Mn 3+ .