Phase separation effects incharge-orderedPr0.5Ca0.5MnO3thin film

CompressedPr_0.5Ca_0.5MnO₃films (250 nm) deposited on LaAlO₃ havebeen studied by Electron Spin Resonance technique under highfrequency and high magnetic field. We show evidences for thepresence of a ferromagnetic phase (FM) embedded in thecharge-order phase (CO), in form of thin layers which sizedepends on the strength and orientation of the magnetic field(parallel or perpendicular to the substrate plane). This FMphase presents an easy plane magnetic anisotropy with ananisotropy constant 100 times bigger than typical bulk values.When the magnetic field is applied perpendicular to thesubstrate plane, the FM phase is strongly coupled to the COphase whereas for the parallel orientation it keeps anindependent ferromagnetic resonance even when the CO phasebecomes antiferromagnetic.