Strain effect and the phase diagram ofLa1−xBaxMnO3thin films

Abstract

We report magnetic and transport properties of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{MnO}}_{3}$ $(x=0.05--0.33)$ epitaxial thin films. Compared with the corresponding bulk materials, the ferromagnetic transition temperature is reduced in the compressive strained ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{MnO}}_{3}$ thin films with $x=0.3$ and 0.33, but enhanced significantly in the tensile strained thin films with $x<~0.2.$ Especially, ferromagnetism and low field colossal magnetoresistance effect were observed around room temperature in $x=0.1$ thin film, and as $x=0.05,$ a spin-canting insulating state in bulk shifts to ferromagnetic metallic state in thin film. The phase diagram of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ba}}_{x}{\mathrm{MnO}}_{3}$ thin films was obtained, and strain effect on these novel properties was discussed.