,Substantial Enhancements of Low-Field Magnetoresistance at Temperatures near77 K with Doping 4% Cu

• 作 者: 袁松柳 张国宏 刘莉 唐洁 张力江 钟强华 杨应平 冯文 刘胜 陈伟 夏正才
• 机 构: Department of Physics, Huazhong University of Science and Technology, Wuhan 430074
• 出 处: 中国物理快报（英文版）
• 发表日期: 2002年12期

We report on investigations of magnetoresistance (MR) in polycrystalline La2/3Ca1/3Mn1-xCuxO3 (x = 0 and 4%) samples prepared by the sol-gel method followed a sintering treatment at 1000℃. For the x = 4% sample, the most remarkable MR effect appears at temperatures near 77K and for magnetic fields lower than 1 T. For fields ～ 0.3 T and at temperatures ～ 77 K, the x = 4% sample exhibits a giant MR effect with Mro (≡△p/p (H = 0)) between ～ 50 and ～ 70%, comparable to the so-called colossal MR response observed in the x = 0 sample for the 3 T field.