摘要
通过室温下的中子衍射和磁性测量对多晶样品Nd0 .5Sr0 .4 Pb0 .1 MnO3的结构和磁性进行了实验研究 .中子衍射结果表明 ,该样品具有正交的钙钛矿结构 ,空间群是Pnma ,即结构发生了晶场畸变 .由M T和R T曲线可知 ,居里温度TC=2 73K ,其特征是随着温度的增加样品经历了从铁磁金属态转变到顺磁半导态 ,且转变温度Tp=2 2 5K ;用锰氧化物晶场和双交换作用的竞争解释了其温度Tp 以下的金属特性 .
Structure, magnetic and transport properties of polycrystalline Nd0.5Sr0.4Pb0.1MnO3 were experimentally studied by neutron powder diffraction at room temperature and magnetic measurement. The neutron diffraction shows that the space group of this orthorhombic structure is Pnma, i. e. its structure exhibits crystal field distortion. Its Curie temperature T-C equals 273 K by the M-T curve. According to the R-T curve, it shows a ferromagnetic metal-paramagnetic semiconductor transition as temperature increases and T-p = 225 K. Using the competing between manganites crystal field and double exchange interaction explains the metal property at room temperature.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第8期2057-2060,共4页
Acta Physica Sinica
基金
中国科学院"百人计划"
国家重点基础研究专项基金 (批准号 :2 0 0 1CB610 60 5 )
国家自然科学基金 (批准号 :5 0 2 72 0 82
10 2 740 14 )资助的课题 .~~
