| Abstract [eng] |
The electrical characteristics of lead titanate thin films, deposited by reactive magnetron layer-by-layer sputtering, are investigated in this thesis. The measurements of films’ morphology by using secondary electron and optical microscopes and structural investigation using X-ray diffraction showed that thin films, deposited on platinum, show non-ferroelectric pyrochlore phase. After annealing tetragonal phase is achieved – however, the quality of the films gets worse because of the occuring compressive thermal stress, making the measurement of electrical characteristics impossible. The quality of films is greatly increased in situ by using 5 nm titanium seeding layer. The hystereses of improved quality films were measured at different amplitudes and frequencies of the external electric field. The coercive field of 234 kV/cm and remnant polarisation of 58 uC/cm2 was achieved. The coercive field dependence on the frequency can be described as: EC µ f b , where b = 0.17. The V-I curve of the films showed that surface-charge-limited conduction is present. |
