  Compressed Pr0.5Ca0.5MnO3 films (250nm) deposited on LaAlO3 have been studied
by Electron Spin Resonance technique under high frequency and high magnetic
field. We show evidences for the presence of a ferromagnetic phase (FM)
embedded in the charge-order phase (CO), in form of thin layers which size
depends on the strength and orientation of the magnetic field (parallel or
perpendicular to the substrate plane). This FM phase presents an easy plane
magnetic anisotropy with an anisotropy constant 100 times bigger than typical
bulk values. When the magnetic field is applied perpendicular to the substrate
plane, the FM phase is strongly coupled to the CO phase whereas for the
parallel orientation it keeps an independent ferromagnetic resonance even when
the CO phase becomes antiferromagnetic.
