Structure and dielectric properties of 80%Pb(Zn_1/3Nb _2/3)O₃-20%PbTiO₃ thin films prepared by modified sol-gel process

80%Pb(Zn_1/3Nb_2/3)O₃-20%PbTiO₃ (PZN-PT) thin films have been prepared on Pt/Ti/SiO₂/Si substrates using a modified sol-gel method. In our method, niobium pentaoxide is used as a substitution instead of niobium ethoxide which is moisture-sensitivity and much more expensive. Microstructure and electrical properties of PZN-PT thin films have been investigated. X-ray diffraction analysis shows that proper annealing temperature of PZN-PT thin films is 600 °C. The PZN-PT thin films annealed at 600 °C are polycrystalline with (111)-preferential orientations. Field-emissiom scanning electron microscope analysis revealed PZN-PT thin films possess well-defined and crack-free microstructure. The thickness of thin films is 290 nm. The Pt/PZN-PT/Pt capacitors have been fabricated and it presents ferroelectric nature. The remanent polarization (Pr), spontaneous polarization (Ps), and the coercive electric field (Ec) are 8.71 μC/cm², 43.06 μC/cm², and 109 kV/cm at 1 MHz, respectively. The dielectric constant (ε_r) and the dissipation factor (tan δ) are about 500.3 and 0.1 at 1 kHz, respectively.