Magnetoresistance reversals and anomalous Hall effect in Mn3SnC and effects of carbon deficiency

The transport behavior of Mn3SnC and Mn3SnC0.8 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 Mn3SnC0.8 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 Mn3SnC but not for Mn3SnC0.8. 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 Mn3SnC0.8.