We have prepared superconducting thin films on MgO(100) substrates by a deposition technique using low pressure plasma flash evaporation. The r.f. plasma was sustained under 20 Torr by a 13.56 MHz r.f. generator operated at 8 kW. The films show various grain orientations depending on the conditions of deposition. With some modifications in the starting material composition, superconducting properties of the best film achieved were T(c) (resistivity rho = 0) = 90 K and J(c) (at 77 K and zero field) = 1.7 x 10(5) A cm2.