Research On Preparation And Properties Of AlN/FeGaB Magnetoelectric Composites

Magnetoelectric composite materials are made up of magnetostrictive material and piezoelectric material, which can achieve a two-way of magnetic-electric energy conversion and show strong magnetic coupling effect. So magnetoelectric composite materials have extensive and important applications in microwave region, current measurement of high-voltage transmission line, magnetic detection in wide-band, magnetic sensors and magnetic signals field. In order to effectively use the magnetic effect to prepare magnetic sensors with excellent performance, we need to study the factors that affect magnetic coupling effect. The magnetic coupling effect largely depends on the performance of magnetostrictive material and piezoelectric material. So we selected aluminum nitride as piezoelectric material and FeGaB as magnetostrictive material, and studied the experiment conditions influence on the properties on the piezoelectric phase and magnetostrictive phase. The main works are listed as follows:A1N films were prepared by magnetron sputtering, and we studied several process conditions that sputtering power, atmosphere pressure, nitrogen and argon volume, substrate temperature and annealing treatment have influence on films properties. According to the experiment results, we found that when the sputtering power is 200 W, the sputtering pressure is 3.75 mT, the nitrogen and argon volume ratio is 3:7, the substrate temperature is 300 C, A1N films grow along the c axis (002), and the films have excellent piezoelectric properties.FeGaB were prepared by magnetron eo-sputtering. The B content in films was controlled by changing the sputtering power of B target. According to the experiment results we found that the films show excellent magnetic properties when the sputtering power of B targets is 50 W.The magnetic sensor, which is made of AIN/FeGaB magnetoelectric composite materials was designed, discussed and theoretical researched, has a high resonant frequency and a very high sensitivity. Therefore it can be used to detect very weak magnetic field, and has a broad application prospect.