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用脉冲激光沉积法在MgO(001)衬底上生长了Pr0.7Sr0.3MnO3/La0.5Ca0.5MnO3/Pr0.7Sr0.3MnO3三层膜,其中Pr0.7Sr0.3MnO3的厚度为36nm,La0.5Ca0.5MnO3厚度分别为6、12、18、24、30和36 nm。通过高分辨X射线衍射的对称扫描和非对称扫描测量了三层膜中Pr0.7Sr0.3MnO3和La0.5Ca0.5MnO3的面外、面内晶格参数,研究了薄膜的晶格应变及其弛豫状况。结果表明,La0.5Ca0.5MnO3厚度的增加使薄膜面外应变完全弛豫,但面内的压应变仍然存在。三层膜应变弛豫状态由块材应变和Jahn-Teller应变共同决定。三层膜的应变弛豫机制与四方畸变的应变弛豫机制不同。块材应变和Jahn-Teller应变之间的相互竞争决定了薄膜的磁输运性质。
Pr0.7Sr0.3MnO3 / La0.5Ca0.5MnO3 / Pr0.7Sr0.3MnO3 trilayer films were grown on the MgO (001) substrate by pulsed laser deposition. The thickness of Pr0.7Sr0.3MnO3 was 36nm, and La0.5Ca0 .5MnO3 thicknesses of 6, 12, 18, 24, 30 and 36 nm, respectively. The out-of-plane and in-plane lattice parameters of Pr0.7Sr0.3MnO3 and La0.5Ca0.5MnO3 in the three-layer films were measured by symmetric scanning and asymmetric scanning of high-resolution X-ray diffraction. The lattice strain and its relaxation Yu situation. The results show that the increase of the thickness of La0.5Ca0.5MnO3 completely relax the out-of-plane strain of the film, but the in-plane compressive strain still exists. The strain relaxation state of the three-layer film is determined by both the bulk strain and the Jahn-Teller strain. The strain relaxation mechanism of the three-layer film is different from the strain relaxation mechanism of the tetragonal distortion. The competition between bulk strain and Jahn-Teller strain determines the magnetic transport properties of the film.