| With the rapid development of modern information technology, micro-electronic technology has been widely used in various fields and people are more and more dependent on the new functional material. Magnetoelectric materials is a kind of material that integrating a variety of properties, which can not only exhibit ferroelectric, ferromagnetic, piezoelectric and other iron properties, but also can may will produce a new performance by the coupling interaction between them.For example, the coupling interaction between ferroelectric and magnetic order parameters, resulting in a new effect which is known as the magnetoelectric effect?Magnetoelectric, the abbreviation for ME?. The magnetoelectric materials have great potential applications in the device domain and have been widely studied.Ba0.5Sr0.5TiO3? BST?,Ni0.9Zn0.1Fe2O4?NZF? and Ba0.5Sr0.5TiO3? BST? /Ni0.9Zn0.1Fe2O4?NZF? have been obtained by sol-gel processing and the crystalline structure and electric properties of thin films are studied by XRD,Ferroelectric tester and PPMS.To begin with, Barium strontium titanate?BST? films with higher properties have been obtained by sol-gel processing on Pt/TiO2/SiO2/Si substrate. And the influence of Solution concentration, coating layers and annealing temperature on the crystalline structure and electric properties of thin films is studied when the annealing time is 450 s. The results show that, BST films have good ferroelectric properties, the saturated polarization value with 18 ?C/cm2, the remaining polarization value with 7.5?C/cm2, the Coercive field value with 230 kV/cm, when the annealing temperature is650 ?,the solution concentration is 0.4 mol/L and the coating layers number is 4. In175 kV/cm electric field, the current density J is about 0.29 ?A/cm2, indicating that the BST thin films can reach the saturation polarization state without breakdownThen, Ni0.9Zn0.1Fe2O4?NZF? films have been obtained by sol-gel processing on Pt/TiO2/SiO2/Si substrate. And the annealing temperature on the crystalline structure and electric properties of thin films is studied. The results show that when the annealing temperature is 500 ?, the saturation magnetization is about 106 emu·cm-3and remanent magnetization is about 34 emu·cm-3,the coercive force is about 1223 Oe;when the annealing temperature is 600 ?, the saturation magnetization is about 139emu·cm-3 and remanent magnetization is about 47 emu·cm-3,the coercive force is about 1563 Oe; when the annealing temperature is 700 ?, the saturation magnetization is about 112 emu·cm-3 and remanent magnetization is about 36emu·cm-3,the coercive force is about 652 Oe. With the increase of temperature, the lattice constant of NZF thin films decreases and the grain size increases gradually. In addition, with the increase of annealing temperature, the lattice constant of NZF thin films gradually decreases, and the grain size increases gradually.Finally, Ba0.5Sr0.5TiO3/Ni0.9Zn0.1Fe2O4?BST/NZF? magnetoelectric composite films have been obtained by sol-gel processing on Pt/TiO2/SiO2/Si substrate. And the annealing temperature on the crystalline structure and electric properties of thin films is studied. The results show that have good ferroelectric and magnetoelectric properties, the saturated polarization value with 19.5 ?C/cm2, the remaining polarization value with 5.1 ?C/cm2, the Coercive field value with 115 kV/cm, the saturation magnetization is about 160 emu·cm-3 and remanent magnetization is about55 emu·cm-3,the coercive force is about 1225 Oe when the annealing temperature is650 ? and the annealing time is 500 s. Besides, the composite films magnetoelectric coupling coefficient were theoretically analyzed and ?E31 is 580 mV/cm?Oe without considering the effect of substrate clamping and ?E31 is decrease with the increasing of the volume fraction in the substrate when considering the effect of substrate clamping. |
PDF Full Text Request