BaTiO₃-based Ferroelectric Heterostructures And Their Magnetoelectric Properties

With the vigorous development of science and continuous innovation of technology,the rapid development of high-tech industry,led by microelectronics industry,electronic information technology and technology manufacturing industry,has put forward higher requirements for the performance of functional materials,and the miniaturization and integration of devices is the trend of the times.The materials with single performance can no longer meet people's needs,thence it is necessary to find matching multi-functional materials.New multifunctional materials for devices have become a research hotspot.At present,the magnetoelectric coupling effect of multiferroic magnetoelectric composites can be used in many fields,such as sensors,transducers,filters,oscillators,phase shifters,memories,etc.Through the investigation and researchhis,this paper has done the following research.The influence of the annealing temperature,the number of coating layers and the concentration of sol on the microstructure and multiferroic properties of the films were investigated by sol-gel method(Sol-gel)first.The optimum technological parameters were obtained:the sol concentration is 0.4 mol/L,the number of spin coating layers is 4,and the annealing temperature is 700?,Secondly,the effects of bottom electrode,laser energy,sputtering oxygen pressure,deposition time,deposition temperature and target spacing on the microstructure and properties of ferroelectric thin film BTO were investigated by laser pulse deposition(PLD).The best process parameters were obtained:laser energy is 240 MJ,sputtering oxygen pressure is 13 PA,deposition temperature is 750?,deposition time is 30 min and target spacing is 50 mm,respectively.Finally,multiferroic NFO/BTO magnetoelectric composite films were prepared by PLD.The results showed that NFO/BTO films exhibit excellent magnetoelectric coupling properties at room temperature.When the bias DC magnetic field is about 600 Oe,the magnetoelectric coupling coefficient of NFO/BTO composite films reach the maximum of 57 mVcm-1·Oe-1,providing a basis for further exploring the coupling mechanism of multiferroic magnetoelectric composite and application in new multifunctional devices.