不同厚度的La_(2/3)Sr_(1/3)MnO_3多晶薄膜输运性质研究  

Thickness-dependent transport properties of La2/3Sri/3MnO3 polycrystalline films

作　　者：蒋晓龙[1] 徐庆宇[1] 桑海[1] 都有为[1] 

机构地区：[1]南京大学固体微结构物理实验室,江苏南京210093

出　　处：《功能材料》2003年第2期231-231,233,共2页Journal of Functional Materials

基　　金：国家重点基础研究发展规划资助项目(G1999064508);国家自然科学基金重大资助项目(19890310(4))

摘　　要：运用磁控溅射的方法,在表面氧化的Si(100)基片上制备了一系列不同厚度的La2/3Sr1/3MnO3多晶薄膜。根据对输运的研究,发现存在一个厚度73nm.当t>73nm的时候,薄膜呈现出与块材类似的输运特点,而当t<73nm的时候,薄膜的电阻太大以至于薄膜的金属-绝缘体转变温度(Tp)变得不可测量。X射线衍射(XRD)结果显示:在t=73nm附近存在一个结构的转变。这表明La2/3Sr1/3MnO3 不同厚度多晶薄膜的输运性质的不同或许来自结构的转变。A series of La2/3Sr1/3MnO3 polycrystalline films with various thickness t were prepared on Si(100) substrate with oxidized surface using magnetron sputtering technique. A critical thickness of about 73nm was observed upon their transport properties. As t >73nmt the films show the bulk-like transport properties. While as t<73nm, the resistance of the films was too large and the metal-insulator transition temperature (Tp) becomes unmeasurable. The results of X-ray diffraction (XRD) show a structure phase transition taking place around t = 73nm. It suggests that the phase transition may account for the thickness-dependent transport properties of La2/3 Sr1/3 MnO3 polycrystalline films.

关 键 词：La2/3Sr1/3MnO3多晶薄膜 输运性质 磁控溅射 厚度 结构 

分 类 号：O484[理学—固体物理]