液氦温区La_(2/3)Ca_(1/3)Mn_(1-x)Cu_xO_3(x=0.15)体系的磁电阻弛豫效应  

MAGNETORESISTANCE RELAXATION EFFECT FOR La _(2/3) Ca_(1/3) Mn_(1-x) Cu_x O_3 ( x =0.15) SYSTEM IN LIQUID\|HELIUM TEMPERATURE REGIME

作　　者：李广[1] 姜勇 孙霞[1] 汤萍[1] 黄真[1] 王胜[1] 袁松柳 

机构地区：[1]中国科学院等离子体物理研究所,合肥230031

出　　处：《物理学报》2000年第1期124-127,共4页Acta Physica Sinica

摘　　要：实验上研究了液氦温区Ｌａ２／３Ｃａ１／３ Ｍｎ１ － ｘＣｕｘＯ３（ｘ＝ ０－１５）单相多晶样品给定磁场下的电阻随时间的变化，发现磁电阻随时间变化并非遵从对数规律而是呈指数型变化行为．对这一指数型磁电阻弛豫行为的可能起因进行了讨论，指出这是与Ｍｎ 位上ＣｕThe time dependence of resistance under certain magnetic fields in liquid\|helium temperature regime for single\|phase polycrystalline La 2/3 Ca 1/3 Mn 1-x Cu\- x O\-3(\%x\%=0.15) have been experimentally studied.It was found that the behavior does not observe the logarithm law, R ∝ln t ,but presents an exponent\|decaying dependence instead.A possible origin for this exponent\|decaying resistance relaxation was discussed in the paper.It was pointed out that the behavior is related to magnetic impurities that are introduced into the system by Cu\|doping on Mn sites.

关 键 词：液氦温区 铁磁材料 磁电阻 驰豫效应 

分 类 号：TM277[一般工业技术—材料科学与工程]