【摘要】 实验研究了Ｍｎ位上Ｃｕ掺杂对Ｌａ２／３Ｃａ１／３Ｍｎ１－ｘＣｕｘＯｙ单相块材液氮温度磁电阻效应的影响．结果表明，在最佳掺杂（ｘ≈０１５）的情况下，样品表现出非常明显的磁电阻效应，且磁电阻的主要变化发生在１Ｔ以下的低磁场下；当磁场增加到６Ｔ时，该样品的磁电阻效应比高达约５×１０４％，相对于偏离最佳掺杂的样品，提高了近三个数量级．更多还原

【Abstract】 Abstract We studied the influence of Cu doping in Mn sites of single phase bulk materials La 2/3 Ca 1/3 Mn 1-x Cu x O y on their magnetoresistance effect at liquid nitrogen in experiment. We find that, for the best doped sample ( x ≈0.15), it shows great magnetoresistance effect clearly. Moreover, the main variation of the magnetoresistance is under the field below 1T. The MR ratio rises up to ～5×10 4% when the field is increased to 6T. It increases three orders of magnitude compared with samples deviated from the best doping.更多还原