Ferroelectric-superconductor structures properties

Abstract

At the present time the urgent direction is to investigate the possibilities of new materials as a base for further improvement of very large-scale integration in order to create elements of submicron digital circuits with improved characteristics. The paper presents and discusses the results of measurements of volt-farad characteristics of structures with PbTiO3/YBa2Cu3O7-x ferroelectric films on strontium titanate substrate. New data on the characteristics of heterostructures with thin ferroelectric films are obtained, in particular it is shown that in the volt-farad characteristics of the studied structures local violations of the smooth forward sweep in the form of characteristic dips at the values of the applied field strengths close to the coercive ones determined by the ferroelectric hysteresis loops are observed. This effect can be explained by the emergence of built-in charges at the interface between a segmented dielectric and a high-temperature superconductor as a result of the polarization switching dynamics of the segmented dielectric. Quantitative estimates of the corresponding values of the embedded charges are made. Another explanation can be the assumption that the nature of these minima is related to the negative capacitance effect in segmentelectrics during polarization switching. The obtained results of the research serve as a basis for consideration of the observed effects in the design of a number of devices related to this subject area, in particular, non-volatile memory and gates based on MOS transistors, in the design of which heterostructures with ferroelectrics are used.