低温物理学报
低溫物理學報
저온물이학보
CHINESE JOURNAL OF LOW TEMPERATURE PHYSICS
2008年
4期
293-297
,共5页
渗流%钙钛矿%磁场%温度
滲流%鈣鈦礦%磁場%溫度
삼류%개태광%자장%온도
percolation%perovskite%magnetic field%temperature
本文用渗流模型研究T(La1-xBx)2/3Ca1/2MnO3系统由顺磁性向铁磁性转换过程中外磁场与转换温度的关系.在平均场理论中,电阻是外磁场和温度的函数.我们发现:当外加磁场不太强时,转化温度随着外磁场的增加而线性地增加.并计算了该系统的热容量.我们理论上的计算与最近的实验观察相当符合.
本文用滲流模型研究T(La1-xBx)2/3Ca1/2MnO3繫統由順磁性嚮鐵磁性轉換過程中外磁場與轉換溫度的關繫.在平均場理論中,電阻是外磁場和溫度的函數.我們髮現:噹外加磁場不太彊時,轉化溫度隨著外磁場的增加而線性地增加.併計算瞭該繫統的熱容量.我們理論上的計算與最近的實驗觀察相噹符閤.
본문용삼류모형연구T(La1-xBx)2/3Ca1/2MnO3계통유순자성향철자성전환과정중외자장여전환온도적관계.재평균장이론중,전조시외자장화온도적함수.아문발현:당외가자장불태강시,전화온도수착외자장적증가이선성지증가.병계산료해계통적열용량.아문이론상적계산여최근적실험관찰상당부합.
On basis of a magnetic percolation model, magnetic transition has been studied for (La1-xBx)Ca1/3 MnO3 system, consisting of paramagnetie and ferromagnetic domains. In the mean-field approach,magnetic resistance as a function of temperature and magnetic field is derived analytically. Subsequently,the thermal capacitance and magnetic resistance are calculated numerically, and compared with recent measurements. It is found there is linear dependence of the critical temperature on the magnetic field,provided the magnetic field is not too strong. The theoretical predications agree well with experiments.