Comment on 'The Origin of Magnetism in Mn-Doped SrTiO_3'

摘要

Multiferroic materials, combining at least two of three properties: ferromagnetism, ferroelectricity, and ferroelasticity in the same phase, have been widely studied during the last years and have tremendous potential for multifunctional applications, despite difficulties to obtain intrinsic magnetoelectric multi-ferroics. In view of this sparsity, weakly doped Sr_(1-x)Mn_xTiO_3 ceramics were found to be a particularly efficient exception. In addition to its enhanced antiferrodistortive elastic features, it reveals both polar glass electric and spin glass magnetic behavior, thus representing the first ever multiglass. For x = 0.02, polar glass freezing due to the off-center displacement of Mn~(2+) ions on the Sr ("A") sites was found to trigger spin glass freezing. Frequency dependent peaks in the temperature dependence of the magnetic susceptibility and magnetoelectric coupling were observed below 38 K and attributed to intrinsic spin coupline via frustrated antiferromagnetic superexchange.