Comparison of Ca-doped and La-doped PT films for pyroelectric sensors

A comparison of pyroelectric and electrical properties of sol gel derived lead calcium titanate PCT with 20%, 24% and 28% Ca and lead lanthanum titanate PLT with 4%, 8% and 12% La thin films has been made. Investigations have been made on the structure, surface morphology, dielectric and electrical properties of the thin films. XRD patterns show that the films annealed at 650°C exhibit tetragonal structure with perovskite phase. AFM images are characterized by slight surface roughness with a uniform densely packed structure. Dielectric, pyroelectric and electrical studies carried out on these films have been compared. The pyroelectric figures of merit have also been calculated. These studies show that PCT with 24% Ca is the most suitable for pyroelectric sensors.