Raman光谱研究厚度对La0.9Sr0.1MnO3/Si薄膜结构的影响

通过溶胶-凝胶旋涂方法结合后退火工艺在Si（100）上制备了不同厚度的La_0.9Sr_0.1MnO₃（LSMO）薄膜，利用X射线衍射（XRD）和共焦显微拉曼散射（Raman）研究了LSMO/Si（100）薄膜的微结构．研究结果表明90 nm厚的LSMO薄膜具有正交相结构，当厚度大于150 nm时，薄膜具有菱方相结构. 150 nm厚的薄膜的Raman图谱中，490 cm^-1和602 cm^-1正交结构 关键词： 薄膜 1-xSr_xMnO₃')" href="#">La_1-xSr_xMnO₃ 共焦显微拉曼 微结构

Thickness dependence of microstructure for La_(0.9)Sr_(0.1)MnO_3/Si films determined by micro-Raman spectroscopy

La_(0.9)Sr_(0.1)MnO_3 films on Si (100) substrate of different thickness were prepared by sol-gel routine, and the microstmcture of LSMO/Si was studied by XRD and confocal micro Raman spectroscopy. Both XRD and Raman results show different structures in LSMO films of different thickness. There are two strong peaks around 490 cm~(-1) and 600 cm~(-1) that is characteristic of Jahn-Teller distortion in spectra and characteristic peak of rhombohedra], structure of the film with thickness of 90 nm, which show the coexistence of two phases. Lattice constants of LSMO film vary with film thickness. Lattice constants vary as film thickness increases, which is because the tilting angle of MnO_6 octahedron and the bond length of Mn-O increase as film thickness increases. Raman spectra of 532 nm-laser and 325 nm-laser show, that there are two phases existing in LSMO/Si film, namely the phase in LSMO/Si interface, and the rhombohedral phase in the surface.