稀土钴氧化物的磁特性和输运性质强烈依靠稀土离子和它们的精细结构.通过Raman散射研究了稀土离子在两种结构中的作用.当R=La、Ce、Pr、Nd,时,RCoO_3化合物为立方结构(Pm~3m),而对于小离子半径(R=Sm、Eu、Gd和Dy),RCoO_3化合物存在于正交结构中[空间群为Pnma(D_(2h)~(16)),Z=4].按照其晶体结构和Raman行为,将RCoO_3化合物分成三个群体:一组包含La、Ce、Pr、Nd,另一组包含Sm、Eu、Gd、Dy,第三组包含Tm、Yb 、Lu 和Er.
The magnetic and transport properties of the rare-earth cobalt oxides RCoO_3 are strongly dependent on the rare earth ion and their detailed structure.The function of rare earth ion in the two structures were studied through Raman diffraction spectra. The results show RCoO_3 compounds present the Pm～3m cubic structure for R=La, Ce, Pr, Nd ,while compounds with smaller ionic radii (R=Sm, Eu, Gd and Dy) can be obtained in the orthorhombic structure [space group Pnma (D_(2h)~(16)), Z=4]. According to the structural and Raman behavior, RCoO_3 compounds can be classified into three groups: one includes La, Ce, Pr, Nd, the other one includes Sm, Eu, Gd, Dy, and the third includes Tm, Yb , Lu , Er.
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