  We report synthesis of phase pure multiferroic YMnO3 thin films on sapphire
(0001)with conducting ZnGaO buffer contact layer. Films were prepared by using
pulsed laser deposition technique and characterized using x-ray
diffraction(XRD), Scanning electron microscopy (SEM), Energy dispersive
absorption spectroscopy (EDAX) and magnetic field dependent dielectric
measurement techniques. Structural characterizations indicated phase purity and
epitaxial nature of the films. The dielectric response indicated an anomaly in
dielectric constant and tand in the vicinity of 30 K, well below the bulk Neel
temperature ~ 70 K. This anomaly in dielectric constant and tand and its
magnetic field dependence is explained as an influence of strain due to lattice
mismatch between the substrate and YMnO3 film. A substantial enhancement in
magnetocapacitance was also observed for magnetic field applied parallel to ab
plane of the film. Our results show that it is possible to tune the
multiferroic property of YMnO3 via changes in ferroelastic route.
