Intrinsic paramagnetism and aggregation of manganese dopants in SrTiO3.

Using local-probe magnetic-characterization techniques of muon spin relaxation and electron spin resonance we have investigated the Mn-induced magnetism of the wide-band-gap perovskite SrTiO3. Our results clearly demonstrate that this diluted magnetic oxide remains paramagnetic down to low temperatures for both doping cases, i.e., when Mn substitutes for Sr or Ti. In addition, both experimental techniques have revealed that the distribution of individual Mn2+ and Mn4+ ions is nonrandom, as these ions partially aggregate into nanosized clusters. [ABSTRACT FROM AUTHOR]