Sr0.25Ba0.75Nb2O6 (SBN) thin films postannealed at 750 °C for 30 min were epitaxially grown in the [00l] direction on p-type (100) Si substrates by the rf magnetron sputtering method. The capacitance–voltage (C–V) characteristics of Au/SBN/Si capacitors, which depend on postannealing conditions, were measured. The C–V curve of the crystalline SBN film had a hysteresis curve with a clockwise rotation. The memory window and surface charge density calculated from the hysteresis loop are 2.1 V and 85 nC/cm2, respectively. From the data of a deep level transient spectroscopy, the activation energies of major traps in the crystalline SBN film obtained were about Ev+0.26 eV and Ev+0.28 eV, by using the Arrhenius plot. © 2000 American Institute of Physics.