A Study on Raman Spectra of Cubic Rare Earth Oxides Xue Lihui; Tie Liyun; Lin Yi Raman spectra for cubic sesquioxides of rare earths RE2O3 (RE = Dy, Ho, Y, Er, Tm, Yb, Lu, Sc ), which were finely divided powders of spectrographic purity, are easy to be cluttered with photoluminescence lines when visible laser sources are used as excitations. The visible region excitation spectra excited by different pump lines and absorption spectra, have been used to rid Raman peaks from photoluminescence lines in the excitation spectra of the RE2O3. The results exhibit the cubic RE2O3 have similar Raman spectra and the strongest band between 350 and 420 cm-1 in particular, caused by stretching vibrations of REO6 octahedron, shifts almost linearly to lower frequencies with increasing metal ionic radii, further proves the theory of lanthanide contraction. cubic rare earth oxides; Raman spectra; photoluminescence; lanthanide contraction