Preparation,Microstructure And Magnetic Properties Of (Ag)/Fe/Ag Nanogranular Films

The research about the microstructure and magnetic properties of ferromagnetic metal films has attracted much attention in magnetism domain. This research has been of both technology and scientific interest. In present paper, nanogranular and ferromagnetic metal films were prepared by facing magnetron sputtering method. The magnetic properties and microstructure of these films have been investigated in detail by VSM, XRD and SPM.The main research results are summarized as follows:1. Ag(x nm) /Fe (35 nm) /Ag (x nm) (x = 1,2,3,4, 5 nm) films have been prepared using a dc facing magnetron sputtering method. The structure and magnetic properties of the films were researched. It has been found that the structure and magnetic properties of the films depend strongly on the Ag layer thickness. The coercivity of Ag(3 nm) /Fe (35 nm) /Ag (3 nm) film reaches about 135 Oe. The granulars becomes fine and the surface mean roughness of the films is 0.7nm. XRD suggested that the origin of large coercivity is grains shape anisotropy.2. Ag(3 nm)/Fe(x nm)/Ag(3 nm) films have been fabricated using a dc facing magnetron sputtering method. The results indicate that the structure and magnetic properties depend strongly on Fe layer thickness. The perpendicular coercivity of the film reaches about 135 Oe just at x =35 nm . AFM images and MFM images show the average grain size and average magnetic cluster size are small.3. Ag(3 nm)/Fe(35 nm)/Ag(3 nm) films were prepared by magnetron sputtering. The structure and magnetic properties depend strongly on the postannealing temperature. The coercivity values first decrease then increase as postannealing temperature increase. The coercivity value reaches the maximum at Ta=500℃. The perpendicular coercivity and the average roughness are obtained about 3.3 kOe and 1.2 nm. We analyzed theδM curves of Ag(3 nm)/Fe(35 nm)/Ag(3 nm) annealed at 500℃for 30 min. The shape of curve shows negative deviations, so we thick that the exchange interaction is mitigated,magnetostatic interactions is the major.4. Fe(35 nm)/Ag(3 nm) films were prepared by magnetron sputtering. It has been found that the high perpendicular coercivity is obtained in the film annealed at 500oC for30 min, and about 522 Oe . The structure and magnetic properties depend strongly on the postannealing temperature.