EXTERNALLY DETERMINED AND INTRINSIC CONTRIBUTIONS TO THE POLARIZATIONSWITCHING CURRENTS IN SRBI2TA2O9 THIN-FILMS

It has been shown that ferroelectric materials are suitable for non vo latile memories. To replace other technologies these materials have to fulfill several requirements, one is a sufficient switching velocity of the material. At present, memory access times amount to 10 to 50 ns . Hence, ferroelectric materials should exhibit access times similar t o these values. As a result, the polarization switching must be comple ted within a few nanoseconds. This work presents fast pulse switching measurements with speeds equal to the speed in a real memory device. F or all samples studied, a significant increase in the coercive voltage has beer! observed at rise times of the excitation signal of about on e nanosecond. A qualitative model is suggested to explain the behavior of the material at highest speed compared to the hysteresis curve dat a recorded by low frequencies. It is distinguished between externally determined and intrinsic part of the polarization switching current.