On the Novel Biaxial Strain Relaxation Mechanism in Epitaxial Composition Graded La1−xSrxMnO3 Thin Film Synthesized by RF Magnetron Sputtering

Coatings

Yishu Wang²  Minghui Zhang²  Efstathios I. Meletis¹ 

[1] Surface and Nano Engineering Laboratory, Department of Material Science and Engineering, University of Texas at Arlington, Arlington, TX 76013, USA;

关键词: magnetron sputtering;    strontium doped lanthanum manganite;    epitaxial thin films;    functionally graded materials;    thin film characterization;   

DOI  :  10.3390/coatings5040802

来源: mdpi

【 摘 要 】

We report on a novel method to fabricate composition gradient, epitaxial La_1−xSr_xMnO₃ thin films with the objective to alleviate biaxial film strain. In this work, epitaxial, composition gradient La_1−xSr_xMnO₃, and pure LaMnO₃ and La_0.67Sr_0.33MnO₃ thin films were deposited by radio frequency (RF) magnetron sputtering. The crystalline and epitaxy of all films were first studied by symmetric θ–2θ X-ray diffraction (XRD) and low angle XRD experiments. Detailed microstructural characterization across the film thickness was conducted by high-resolution transmission electron microscopy and electron diffraction. Four compositional gradient domains were observed in the La_1−xSr_xMnO₃ film ranging from LaMnO₃ rich to La_0.67Sr_0.33MnO₃ at the surface. A continuous reduction in the lattice parameter was observed accompanied by a significant reduction in the out-of-plane strain in the film. Fabrication of the composition gradient La_1−xSr_xMnO₃ thin film was found to be a powerful method to relieve biaxial strain under critical thickness. Besides, the coexistence of domains with a composition variance is opening up various new possibilities of designing new nanoscale structures with unusual cross coupled properties.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.