Fabrication And Resistance Switching Behaviors Of BZT-BCT/FeCo Thin Films

Multiferroic materials can simultaneously exhibit ferroelectric and ferromagnetic properties.The coexistence of multiple ferroic properties provides the possibility for new functions of devices.In this paper,Ba(Ti_0.8Zr_0.2)O₃-(Ba_0.7Ca_0.3Ti O₃/Fe₆₅Co₃₅（BZT-BCT/Fe Co）multiferroic composite films were constructed.The resistance state of BZT-BCT/Fe Co composite films was regulated by applying bias voltage.The specific research contents are as follows:0.4BZT-0.6BCT lead-free piezoelectric ceramic films with high piezoelectric properties were prepared by magnetron sputtering.The 0.4BZT-0.6BCT films with saturation polarization of 8.13μC/cm²and the piezoelectric displacement of 26?were prepared by optimizing the pressure,oxygen flow rate and argon flow rate.Fe Co films with different sizes were prepared on the optimized 0.4BZT-0.6BCT thin film by ion beam sputtering combined with lithography process.The magnetic properties of 0.4ZT-0.6BCT/Fe Co composite films and the influence of bias voltage on the resistance state of Fe Co films were investigated.The results show that the bias voltage has a significant effect on the I-V characteristics and resistance state of the0.4BZT-0.6BCT/Fe Co film.With the decrease of the size for Fe Co films,the bias voltage increases the I-V characteristics and resistance state of the0.4BZT-0.6BCT/Fe Co film.In addition,Fe Co films with different thicknesses and patterns were prepared on0.5BZT-0.5BCT films to fabricate magnetoelectric memory devices.The ferroelectric and ferromagnetic properties of 0.5BZT-0.5BCT/Fe Co composite films were studied,and the magnetic domain structure was tested and analyzed.The effect of Fe Co films with different thicknesses and patterns on the resistance switching behaviors of0.5BZT-0.5BCT/Fe Co composite films was studied.By applying bias voltage on Fe Co films with different thicknesses grown on 0.5BZT-0.5BCT,the resistance state of ferromagnetic films can be regulated.With the decrease of thickness and the increase of pattern length-width ratio,the regulation of bias voltage on I-V behavior and resistance state of 0.5BZT-0.5BCT/Fe Co films is also optimized.