Microstructure of new colossal magnetoresistance La1–xTexMnO3 (x= 0.1, 0.2) thin films

Abstract

We have used transmission electron microscopy and characterized the microstructure in thin films ofLa1–xTexMnO3 (x = 0.1, 0.2) compounds, which are new additions to the family of colossal magnetoresistance (CMR) oxides. Electron diffraction and high-resolution imaging reveal that Te-doped thin filmswith a thickness of 100 nm for x = 0.1 and 200 nm for x = 0.2 are epitaxially grown on the SrTiO3 (001) substrate. On the basis of electron diffraction patterns obtained from cross-section and plan-view specimens, the new compounds are determined to have an orthorhombic unit cell with lattice parameters ao ≈ 21/2ap = 0.54 nm, bo ≈ 2ap = 0.77 nm, co ≈ 21/2ap = 0.54 nm, where ap is the lattice parameter of an ideal cubic perovskite structure, 0.39 nm. The microstructures in orthorhombic La1–xTexMnO3 compounds are clarified in terms of two 90°-oriented domains, both of which are grown with [101] axis perpendicular to the substrate surface. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)