Preparation Of FeGa Thin Films By Pulsed Laser Deposition And Their Magnetic Properties

With the rapid development of Internet of things,the importance of sensors is increasing.Magnetic sensors play an important role in field detection,current detection,nondestructive testing and geomagnetic navigation.Fe Ga alloy with large magnetostriction is one of the most popular magnetic sensor sensitive component.Fe Ga alloy is a new type of ferromagnetic functional material.Due to the high saturation magnetostriction coefficient,high saturation magnetization,low coercivity,low saturation magnetic field,fast response speed,high Curie temperature and excellent mechanical properties and other characteristics,it has become an important candidate material for ferromagnetic phase in magnetoelectric coupling system.Compared with traditional block materials,thin film materials have an irreplaceable advantage in miniaturization and integration with the rapid development of micro-nano processing technology.This paper starts with Fe Ga film material,Fe Ga films were prepared by pulsed laser deposition and research on static magnetic energy.(1)We explore different substrate temperatures,different growth times,different laser power densities and so on,the process parameters of Fe Ga films grown on single crystal Si and Ga As were gradually developed.Among them,on the Ga As substrate,we observed(001)direction of the D03 structure and thin film growth of preferred orientation.On Si substrate,Fe Ga films maintain good soft magnetic properties.The D03 and A2 phase transition of Fe Ga films can be adjusted by changing Ga As substrate temperature,good soft magnetic performance depends on the(001)direction of the D03 ordered crystal phase.As the temperature continues to rise,the soft magnetic properties will be destroyed.The above results provide the basis data for the application of Fe Ga thin film in the magnetoelectric sensor.(2)In order to further expand Fe Ga thin film application and optimize the soft magnetic properties,we by Fe Ga and Mn alternate growth method prepared Fe Ga Mn alloy films.When the Mn growth frequency is 1 Hz,with the advent of Ga Mn phase,the magnetic moment component is induced to be perpendicular to the surface of the film;when the Mn growth frequency is 3 Hz,film shows good ferromagnetism;when the Mn growth frequency is 5 Hz,the film also shows the coexistence of ferromagnetic and antiferromagnetism.The resistance of the film decreases as the magnetic field becoming larger.With the Mn content is higher,resistance is bigger.(3)In order to further enhance the saturation magnetization of the Fe Ga film,we are in assisted of ion activation sources,through the ventilation with high purity nitrogen,N doped Fe Ga films were successfully prepared by means of high purity nitrogen and the saturation magnetization of Fe Ga films was improved.When Ga As substrate temperature was 400 ?,appears Fe Ga N film structure of(200)direction in the A2 disorderly phase structure.With the increase of nitrogen flux,the crystallinity of ferromagnetic phase Fe Ga N growth on the Si substrate is getting better and better.The results proposed the new train of thought and laid a good foundation for the application of Fe Ga thin film materials.