Spin Ordering in Mn-Doped KTaO3?

The influence of Mn concentration and different processing conditions on the low-temperature magnetic anomaly was reported. The first set of magnetic measurements was performed on the samples homogenized with a pestle and mortar and fired at 1000°C. Weak peaks of secondary tungsten bronze-type phase appeared for the x > 0.03 samples, for which the solid solubility limit is exceeded. The molar magnetic susceptibility of pure KTaO3 remains nearly temperature independent in the 10-300 K range with a slight upturn at T< 10 K due to the residual concentration of magnetic impurities. If the observed anomaly originates from the intrinsic magnetic interactions in Mn-doped KTaO3 its magnitude would be expected to remain constant after exceeding the solid solubility limit. It was also observed that incomplete processing can result in an antiferromagnetic response due to a presence of residual Mn3O4.