摘要
系统研究了(La1-xNdx)0.5Ca0.5MnO3(x=0,0.2,0.4,0.6,0.8,1.0)系列样品的结构、磁性质和电输运性质。研究表明,所有样品的结构都为钙钛矿正交结构(空间群Pbnm),随着掺杂浓度x的增大,样品的晶格参数a,b,c和晶胞体积V都呈减小的趋势;磁性质的研究表明所有样品在低温下均出现电荷有序态,且电荷有序转变温度随着Nd3+的掺杂浓度x的增加而升高;除了Nd0.5Ca0.5MnO3(x=1.0)外,其它样品均出现顺磁-铁磁转变,其转变温度(即居里温度)随着Nd3+的掺杂浓度x的增加而降低;(0.2≤x≤0.8)样品的铁磁态均出现在电荷有序温度以下,表现出再入型(reentrant)铁磁态性质;电输运性质的研究表明,所有样品的电阻率随温度的升高而下降,表现为绝缘体性质。
Structure, magnetic properties and electrical transport properties of （La1-xNdx）0.5Ca0.5MnO3 （x = 0, 0.2, 0.4, 0. 6, 0. 8, 1 ） are investigated systemically. The x-ray diffraction investigation shows that all the compounds are in single phase with the orthorhombic lattice （Pnma space group）. With increasing the Nd3. concentration x, both the lattice parameters and the unit cell volume reduce. Magnetic properties investigations indicate that all the samples undergo the charge ordering transition in the low temperature, and the transition temperatures shift to the high temperature with increasing x. Furthermore, the paramagnetic ferromagnetic transitions occur in all the samples except the Nd0. 5Ca0.5MnO3 （x = 1）, and the Curie temperatures shift to the low temperature with increasing x. For the samples, the ferromagnetic states appear under the charge ordering temperatures, exhibiting the reentrant ferromagnetic transition characteristic. The electrical transport properties exhibit an insulator behavior and the resistivity increases with the temperature decreases in this compound.
出处
《信息记录材料》
2006年第3期18-22,共5页
Information Recording Materials
基金
天津市自然科学基金(043602111)
关键词
锰氧化物
庞磁电阻
相分离
Manganites
Colossal magnetoresistance
Phase separation
