Synthesis of polycrystalline bulk Titanium oxide system dilutely doped with manganese and observation of Mn3O4 cluster-driven low temperature ferromagnetism

Diluted magnetic semiconductors (DMS) have received significant attention in the recent past in view of their sig- nificance for the rapidly developing field of spintronics. In this context, we have examined the case of Titanium ox- ide (TiO2) system dilutely (2 and 5 at %) doped with Manganese (Mn). These bulk polycrystalline samples exhibit rutile structure, which is the most stable structure amongst various configurations of TiO2. The Ti0.98Mn0.02O2 sample shows additional signatures of non-magnetic Mn2O3 in X-ray diffraction studies. Interestingly, Ti0.95Mn0.05O2 exhib- its ferromagnetism at very low temperature. X-ray diffraction studies show additional signatures of the Mn3O4 phase. Ion image and line scanning analysis of these samples using SIMS technique confirm that Mn atoms are not uni- formly dispersed in the matrix and appear to have clustered. The nature of the clustered phase could be ascertained by magnetization measurements, which indicate a low temperature transition at 42 K, which is a characteristic of the Mn3O4 phase.