Study On The Magnetic Anisotropy Of Thin Films Prepared By Oblique Sputtering

With the continuous development of electronic information technology,magnetic films have played an indispensable status and role in the field of electronics.Therefore,the study of the properties and characteristics of magnetic films has become one of the hotspots that researchers are paying attention to in the modern era.Magnetic anisotropy field is one of the important parameters of magnetic thin films,and it will affect the natural resonance frequency of magnetic thin films.Oblique sputtering technique is one of the most common methods in the preparation of magnetic thin films and it can induce an effective magnetic anisotropy field with certain orientation in thin films.By changing the angle of oblique sputtering,the magnetic anisotropy field can be controlled and the effective magnetic anisotropy field with definite orientation can also be produced.Generally,oblique sputtering technique can produce an effective magnetic anisotropy field with initial orientation perpendicular to the in-plane projection direction of the sputtered atom beam,and the effective magnetic anisotropy field increases with the increase of the oblique sputtering angle.Under special conditions,an effective magnetic anisotropy field with initial orientation parallel to the in-plane projection direction of the sputtered atom beam will be generated by the oblique sputtering technique in the materials of different compositions,and it also increases with the increase of the oblique sputtering angle.For the above two cases,the orientation of the effective magnetic anisotropy field varies with the increase of the oblique sputtering angle in different materials,that is,the orientation of magnetic anisotropy field can occur a 90 degrees reversal from perpendicular(parallel)to parallel(perpendicular)direction to the in-plane projection direction of the sputtered atom beam or remain unchanged but the magnitude changes when the oblique sputtering angle increases to a certain value.In this paper,the influence of the oblique sputtering technique on the magnetic anisotropy of magnetic thin films with different material compositions was studied,and in order to understand the variation of magnetic anisotropy at different temperatures,the effect of temperature on the magnetic anisotropy was studied by using polyvinylidene fluoride(PVDF)with anisotropic thermal expansion properties as substrate material combined with oblique sputtering technique.Firstly,a series of magnetic thin films with different compositions(Fe Co Ta,Fe Co B,Fe Ni)were prepared by oblique sputtering technique at room temperature without any induction conditions.The effect of the oblique sputtering technique on the magnetic anisotropy orientation of the magnetic films with different compositions were investigated.It is found that the initial orientation of effective magnetic anisotropy field is parallel to the in-plane projection direction of sputtered atom beam in Fe Co Ta and Fe Co B magnetic thin films,and the effective magnetic anisotropy field increases with the increase of the oblique sputtering angle.Moreover,the orientation of the effective magnetic anisotropy field of both of them occured a 90 degrees reversal when the oblique sputtering angle increases to a certain value.However,in Fe Ni magnetic thin films,the orientation of the effective magnetic anisotropy field is always perpendicular to the in-plane projection direction of sputtered atom beam and it also increases with the increase of the oblique sputtering angle.But when the oblique sputtering angle increases to a certain value,the effective magnetic anisotropy field will decrease.Furthermore,we use the polyvinylidene fluoride(PVDF)with anisotropic thermal expansion properties as substrate to study the variation of magnetic anisotropy of Fe Co Ta,Fe Co B and Fe Ni magnetic films at oblique sputtering angles of 0 degree,25 degree,45 degree,65 degree and 75 degree respectively,and also study the change of magnetic anisotropy within a certain temperature range.It is found that the magnetic anisotropy increases first,then decreases,and then increases again with the increase of oblique sputtering angle for Fe Co Ta magnetic films.Meanwhile,the magnetic anisotropy for Fe Co Ta magnetic thin films grown in the direction of ?32 decreases first and then increases with the increase of temperature when the beta is less than or equal to 45 degree,while it increases continuously when the beta is greater than 45 degree.However,For Fe Co Ta films grown along the ?31 direction,the magnetic anisotropy all decreases first and then increases with the increase of temperature when the beta is less than or greater than 45 degree respectively,while it increases continuously with the increase of temperature when beta is equal to 45 degree.The magnetic anisotropy for Fe Ni magnetic films increases first and then decreases with the increase of oblique sputtering angle.At the same time,the magnetic anisotropy for Fe Ni films grown along the direction of ?32 decreases first and then increases with the increase of temperature when beta is equal to 0 degree and increases continuously when beta is greater than or equal to 25 degree.However,for Fe Ni films grown along the ?31 direction,apart from the vertical sputtering,the magnetic anisotropy decreases monotonously with the increase of temperature at other oblique sputtering angles.The magnetic anisotropy varies with the oblique sputtering angle and temperature in magnetic films with different material compositions.Fe Co B magnetic thin films also have similar and different results with those two kinds of materials.Finally,to summary the work of this paper,and the shortcomings in the work are proposed,meanwhile,the future work of this paper is prospected and discussed.