Magnetoresistance reversals and anomalous Hall effect in Mn 3 SnC and effects of carbon deficiency.

The transport behavior of Mn 3 SnC and Mn 3 SnC 0.8 compounds was investigated. Positive magnetoresistance (MR) and an anomalous Hall effect (AHE) are observed for each compound near respective Curie temperature, T C . The positive MR is reversed during cooling from T C but is reentrant at low temperature. A 20% carbon deficiency of Mn 3 SnC 0.8 enlarges the positive MR at T C and shifts the temperatures for MR reversals. Ferromagnetic (FM) resonance measurements reveal that the MR reversals are related to the competition between FM and antiferromagnetic components of Mn atoms in each compound. A sign change of the Hall resistivity is observed during cooling of Mn 3 SnC but not for Mn 3 SnC 0.8 . A scaling analysis suggests that the AHE in each compound is mostly due to an intrinsic contribution and that the intrinsic contribution is decreased by the carbon deficiency in Mn 3 SnC 0.8 .