Large temperature coefficient of resistivity and magnetoresistance for polycrystalline La0.68Nd0.04Ca0.28MnO3 at low magnetic field

Abstract To obtain comprehensive materials with both high temperature coefficient of resistivity (TCR) and magnetoresistance (MR) at low magnetic fields, the polycrystalline La0.72−xNdxCa0.28MnO3(x = 0.02, 0.04, 0.06, and 0.08) were synthesized using the sol–gel method, which is a significant practical application in magnetic sensors and bolometers. We observe an enhancement of TCR and MR by substituting La3+ with Nd3+. The excellent TCR (19.21 %·K−1) and MR (73.10 %) are observed in La0.68Nd0.04Ca0.28MnO3 at the 1 T magnetic field. Meanwhile, the maximum TCR reaches 22.68 %·K−1 without a magnetic field. This substitution increased the total magnetic moment and a slight increase in average grain size. The Mn3+ and Nd3+ spin within the disordered region realign along the field direction with a magnetic field. Therefore, Nd-doped La0.72Ca0.28MnO3 ceramic materials can effectively improve the material properties.