钙钛矿结构La_(1-x)Ca_xMnO_3的激光拉曼光谱分析  

ANALYSIS OF LASER RAMAN SPECTRUM OFPEROVSKITE La_(1-x)Ca_xMnO_3

作　　者：刘奇[1] 许丹[1] 李广[1] 朱克荣[2] 唐怀保[1] 

机构地区：[1]安徽大学物理与材料科学学院,合肥230039 [2]安徽大学现代实验技术中心,合肥230039

出　　处：《低温物理学报》2013年第2期81-86,共6页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:11174002);安徽大学"211工程"(批准号:KJTD004B和KJJQ007)资助的课题~~

摘　　要：用固相反应法制备了具有钙钛矿结构的La1-xCaxMnO3(x=0和0.33)并对其晶体结构、磁性、电阻和激光显微共聚焦散射拉曼光谱进行了测试、表征和分析.每种样品在激光拉曼光谱上都呈现出高波数峰(～640cm-1)、中波数峰(～500cm-1)和低波数峰(～220cm-1)三个明显的特征峰.它们分别对应锰氧八面体面内氧原子的对称伸缩振动模式,氧原子的反对称伸缩振动模式和氧原子的旋转振动模式.高波数峰随温度的演化呈现出明显的变化行为,并且这种行为及对应的特征温度与材料的磁性和电子输运随温度的变化行为及特征温度基本吻合.但其他两种峰随温度变化没有较为明显的规律性.高波数峰对应的锰氧八面体面内氧原子的对称伸缩振动模式与锰氧化物材料的磁性和电子输运存在本质上的联系.Perovskite-type La1-xCaxMnO3 （x=0 and 0. 33） samples were prepared by a solid-state method. Their crystal structures, magnetism, resistance and laser confocal microscopic Raman spectra were measured, character- ized and analyzed. Three obvious characteristic peaks, high wave number peaks （~640 cm-1 ）, medium wave num- ber peaks （~500 cm-1） and low wave number peaks （~200 cm-1）, appear in Raman spectrum for each sample. They correspond to the symmetric stretching vibration, anti-symmetric stretching vibration, and rotating vibration modes of oxygen atoms in octahedral MnO6. The evolvement of high wave number peaks shows obvious changes with temperature, which is coincided with the variation of magnetism and electronic transport of this material at the same characteristic temperatures. But the other two peaks show no obvious changes with temperature. The symmet- ric stretching vibration mode of oxygen atoms in the octahedron has a substantial relation with magnetism and elec- tronic transport of manganite materials.

关 键 词：锰氧化物 激光拉曼光谱 振动模式分析 

分 类 号：O433.4[机械工程—光学工程]