双层锰氧化物La_(1.2)Sr_(1.8)Mn_2O_7单晶的磁性和电性研究  

Magnetic and Electric Properties of Perovskite Manganites La_(1.2)Sr_(1.8)Mn_2O_7 Single Crystal

作　　者：何利民[1] 冀钰[1] 王洪金[1] 范永生[1] 邢茹[1] 鲁毅[1] 赵建军[1] 

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

出　　处：《稀土》2013年第4期17-20,共4页Chinese Rare Earths

基　　金：国家自然科学基金(11164019);内蒙自然科学基金(2009MS0101;2011MS0101;2011MS0108);内蒙高校科学研究基金(NJZZ11166;NJ10163)

摘　　要：通过浮区炉方法制备钙钛矿双层锰氧化物单晶材料La1.2Sr1.8Mn2O7,利用X射线衍射、劳埃衍射确定单晶的质量;选择高质量的单晶片切割成长方形,用超导量子磁强计测量其磁性;采用四端法测量其输运性质。XRD测量表明,La1.2Sr1.8Mn2O7粉末为单相。磁性测量表明,在高温区域样品的磁化强度很小,表现为顺磁态,在T=110 K附近磁化强度迅速增大,并且随温度的降低逐渐达到饱和,显示出铁磁性的特征。磁电阻的测量显示出单晶样品缺陷比多晶样品少,电阻率非常小。Single crystals of La1,2Srl.sMn207 were melt - grown in flowing air in a floating - zone optical image furnace. The quality of the single crystals was determined with x - ray diffraction and Lane diffraction. Selected high quality single chips were cut into rectangularity and their magnetic properties and transport properties were measured by SQUID four terminal meth- od, respectively. XRD pattern indicates that the powedr is a single phase. The sample shows paramagnetic in high temperatrnre. The magnetization increased rapidly at 110K and was saturated gradually with decrease of temperature, Single crystal sample has less defects than polyerystalline sample and the resistivity is very small.

关 键 词：单晶 相分离 磁电特性 

分 类 号：O482.52[理学—固体物理] O614.33[理学—物理]