Eu掺杂层状钙钛矿Nd_(1.2)Sr_(1.8)Mn_2O_7的类Griffiths相研究  

A STUDY ON THE GRIFFITHS-LIKE PHASE OF THEPEROVSKITE MANGANITES SAMPLES Nd_(1.2-x)Eu_xSr_(1.8)Mn_2O_7(x=0,0.05,0.1)

作　　者：王芳[1] 万素磊 周敏[1] 吴鸿业[1] 徐宝[1] 孙运斌[1] 鲁毅[2] 赵建军[2] 

机构地区：[1]包头师范学院物理科学与技术学院,内蒙古包头014030 [2]内蒙古自治区磁学与磁性材料重点实验室培育项目包头师范学院,内蒙古包头014030

出　　处：《低温物理学报》2016年第2期145-149,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:11164019;51562032;61565013);内蒙古自治区科学基金(批准号:2015MS0109);内蒙高校科学研究基金(批准号:NJZZ11166;NJZY12202);包头市科学技术局产学研合作项目(批准号:2014X1014-01);内蒙古自治区研究生科研创新项目(批准号:S201510127(S01));包头师范学院青年科技基金(批准号:BSYKJ2015-22)资助的课题~~

摘　　要：采用传统固相反应法制备Nd_(1.2-x)Eu_xSr_(1.8)Mn_2O_7(x=0,0.05,0.1)多晶样品,通过测量样品的磁化强度随温度变化曲线(M-T曲线)、磁化强度随外场的变化曲线(M-H曲线)并对样品的M-T曲线进行居里外斯拟合得到不同磁场下磁化率倒数与温度的变化曲线(X^(-1)-T曲线)和温度与磁化率的乘积随温度变化曲线(X·T-T曲线),以及类Griffiths相模型的拟合,研究了Nd_(1.2-x)Eu_xSr_(1.8)Mn_2O_7(x=0,0.05,0.1)多晶样品的磁性及类Griffiths相(Griffiths-like phase)现象.研究结果表明,三个样品都体现出类Griffiths相现象,分别在126K—282K,117K—282K和101K—282K范围内观察到类Griffiths相,同时发现掺杂使得三个样品的居里外斯温度(T_C)、三维铁磁有序温度(T_c^(3D))和二维铁磁有序温度(T_c^(2D))降低,但对类Griffiths相温度(T_C≈282K)没有明显影响.Nd1.2Sr1.8Mn2O7 （x=0,0. 05,0. 1）polycrystalline samples were prepared by solid state reaction method and the Griffiths-like phase phenomena in this samples were investigated by measuring the M-T curve.M-H curve and through the Curie-Weiss and Griffiths model fitting. For three samples, experimental results suggest there exists the Griffiths-like phase in temperature ranges 126K-282K, 117K-282K and 101K-282K for x = 0. 0 sample, x=0. 05 sample and x=0. 1 sample, respectively. It＇s found that doping contributes to the decrease of the Curie-Weiss Temperature（from Tc0=119K for x=0. 0,Tcl=113K for x=0. 05 to Tc2=80K for x=0. 1） ,three- dimensional long-range ferromagnetic ordering temperature （from Tc03D= 126K for x= 0. 0, Tc13D= 117K for x= 0. 05 to Tc23D=101K for x=0. 1） and two-dimensional long-range ferromagnetic ordering temperature （from Tc02D= 178K for x=0. 0 , Tc12D=169K for x=0. 05 to Tc22D=156K for x=0. 1）, but has no obvious effects on the Griffiths-like temperature （TG=375K）.

关 键 词：磁性 居里外斯 类Griffiths相 

分 类 号：O469[理学—凝聚态物理]