Dielectric properties and strain analysis in paraelectric ZrTiO4 thin films deposited by DC magnetron sputtering

The dielectric constants and dielectric losses of ZrTiO4 thin films deposited by DC magnetron reactive sputtering were investigated. The paraelectric properties were measured in the 100 kHz range, and compared with an equivalent circuit model. As the deposition temperature increased (up to 600°C), the dielectric losses (tan δ) decreased (down to 0.017 ± 0.007), while the dielectric constants (Ε) were in the range of 35 ± 7. Post annealing at 800°C in oxygen for 2 h reduced tan δ down to 0.005 ± 0.001, higher than those of well-sintered bulk ZrTiO4. The systematic trend of tan δ as a function of deposition temperature and post annealing showed good correlations with strains in ZrTiO4 thin films deduced from the broadening of X-ray diffraction peak.