Transport properties, magnetoresistance, and temperature coefficient of resistance of perovskite NdMnO₃

Magnetoresistance and temperature coefficient of resistance (TCR) of manganites with ferromagnetism have been reported extensively, but the magnetoresistance and TCR of antiferromagnetic manganites are scarce. The transport properties, TCR, and magnetoresistance effect of antiferromagnetic NdMnO₃ have been studied in this work. NdMnO₃ samples exhibit semiconductor conductivity, and with the different applied magnetic fields, they still maintain semiconductor characteristics and have considerable stability. Under an applied magnetic field of 6 T, a small negative magnetoresistance of 8% appears near 150 K. Moreover, the conduction mechanism and TCR of NdMnO₃ are studied. Three models, thermal activation (TA) model, small polaron (SP) model, and variable range jump (VRH) model, are used to analyze the electrical transport of NdMnO₃ samples. The results show that the transport behavior of NdMnO₃ samples is more consistent with the TA model. The maximum TCR is 9.4% K⁻¹ within the low temperature region (above liquid nitrogen temperature). The TCR decreases with increasing temperature and it remains 2.5% K⁻¹ near room temperature. Antiferromagnetic NdMnO₃ has good TCR performance, which can be applied to temperature sensing field and has good application prospect in antiferromagnetic insulating electronic devices.