Large temperature coefficient of resistivity and magnetoresistance for polycrystalline La_(0.68)Nd_(0.04)Ca_(0.28)MnO_3 at low magnetic field

摘要

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 Ta0.68Nd0.04Ca0.28MnO3 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.