Ferromagnetism in Mechanically Milled Sn1-xCoxO2 (x=0 to 0.10) Compounds

Co-doped SnO2 based diluted magnetic oxides were prepared by mechanical alloying followed by high temperature annealing. XRD patterns could be refined to P4(2)/mnm space group with typical lattice parameters a=b=4.733 and c=3.184 . Presence of a minor spinel structure based impurity phase was detected. Room temperature ferromagnetism was observed with a maximum saturation magnetization of 5.9 emu/g for Sn0.98Co0.02O2 sample. The magnetization data after subtracting the contribution from the impurity phase could be analyzed based on a bound magnetic polaron model. Temperature variation of magnetization exhibits clear paramagnetic to ferromagnetic transition with a maximum T (c) of 640 K for 2 at% Co-doped sample. Susceptibility in paramagnetic region could be fitted to the Curie-Weiss law.