Eur. Phys. J. B 20, 177-181 (2001)
https://doi.org/10.1007/BF01315688

Effect of Cu doping at the Mn site on the transport and magnetic behaviors of La_2/3Ca_1/3MnO₃

Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, PR China

Corresponding author: ^a yuansl@hust.edu.cn

Received: 9 August 2000
Revised: 14 November 2000
Published online: 15 March 2001

Abstract

We show that the replacement of Mn with Cu, without any structure change, strongly affects the transport and magnetic behaviors in La_2/3Ca_1/3 MnCu_xO (0.3). Doping largely shifts the insulator-metal transition towards the low-temperature regime and causes substantial enhancements in both resistance and magnetoresistance near the transition for doping range of , and further doping to shows insulating behavior. For 15% doping, the sample shows large magnetoresistances (~10⁴% ) over the whole low temperature range. Magnetization measurement at helium temperature reveals that samples for and basically show ferromagnetic (FM) and antiferromagnetic (AF) behaviors, respectively, while the 15% Cu doped sample undergoes a metamagnetic transition from AF state to FM state on increasing field. We argue that doping introduces the AF insulating phase into the system, causing unusual transport and magnetic behaviors.