Structures and dielectric properties of Bi1.5Zn1.0Nb1.5-xTixO7 (x=0, 0.05, and 0.10) thin films

B-site Ti-substituted Bi1.5Zn1.0Nb1.5O7 (Bi1.5Zn1.0Nb1.5-xTixO7, x=0, 0.05, and 0.10) thin films have been fabricated on Pt/Ti/SiO2/Si substrates by pulsed laser deposition. The x-ray diffraction and scanning electron microscopy measurements show that the films have a single phase and are well crystallized and homogeneous. Dielectric properties are investigated as function of temperature and frequency. It is found that the Ti substitution increases the dielectric constant. At 10 kHz, the room temperature dielectric constant and loss tangent (epsilon, tan delta) are (163, 0.006), (182, 0.014), (197, 0.010) for the films with x=0, 0.05, and 0.10, respectively. In a wide temperature and frequency range (-100 degrees C similar to 50 degrees C, 1 kHz similar to 1 MHz), the dielectric constant is almost constant. However, below -100 degrees C, a dielectric relaxation depending on Ti content is observed. The relationship between structure and property of this thin film system is discussed. (c) 2007 American Institute of Physics.