  We report structural, optical, temperature and frequency dependent
dielectric, and energy storage properties of pulsed laser deposited (100)
highly textured BaZr(x)Ti(1-x)O3 (x = 0.3, 0.4 and 0.5) relaxor ferroelectric
thin films on La0.7Sr0.3MnO3/MgO substrates which make this compound as a
potential lead-free capacitive energy storage material for scalable electronic
devices. A high dielectric constant of ~1400 - 3500 and a low dielectric loss
of <0.025 were achieved at 10 kHz for all three compositions at ambient
conditions. Ultrahigh stored and recoverable electrostatic energy densities as
high as 214 +/- 1 and 156 +/- 1 J/cm3, respectively, were demonstrated at a
sustained high electric field of ~3 MV/cm with an efficiency of 72.8 +/- 0.6 %
in optimum 30% Zr substituted BaTiO3 composition.
