Micro Structure And Magnetic Properties Of Ferromagnetic Metal 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 technological and scientific interest. In present paper, Nanogranular C/Co/C, Ti/Co/Ti, Ti/Ni/Ti and Ti/Fe/Ti 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. Nanogranular C/Co/C films have been prepared by facing magnetron sputtering method. The ageing effect of the structure and magnetic properties of the C/Co/C films was investigated. It has been found that the magnetic properties of as-deposited and annealed films have not destroyed and slightly improved to a certain extent. It is very important for magnetic recording media application. In addition, activation volume of the annealed sample is been calculated. The magnetic activation volume of the magnetic particles has been reduced to about 0.9 of the former.2. Ti/Co/Ti 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 Ti/Co/Ti films depend strongly on the Ti layer thickness, Co layer thickness and annealed temperature. The hexagonal-close-packed (hcp) Co (002) structure is dominant in all films. The out-of-plane coercivity of as-deposited Ti (5nm)/Co (54nm) /Ti (5nm) film reaches about 2 kOe. It can be attributed to the large magnetic crystal anisotropy of the magnetic grains. The granulars becomes fine and the surface mean roughness of the films is decreased after annealing. But the properties of the samples are not improved through annealed.3. Ti/Ni/Ti films have been fabricated using a dc facing magnetron sputtering method. The results indicate that the magnetic moment of Ti (3nm)/Ni (10nm)/Ti (3nm) film lies on the out-of plane predominately and shows strong perpendicular anisotropy. The perpendicular coercivity of the Ti (3nm)/Ni (10nm)/Ti (3nm) film reaches about 1.5 kOe. It is suggested that the origin of large coercivity is strong stress anisotropy.4. Ti/Fe/Ti films were prepared by magnetron sputtering. It has been found that the high perpendicular coercivity and large remanent squareness is obtained in the Ti (16nm)/ Fe (30 nm)/Ti (16 nm) film annealed at 500oC for 30 min, and about 6.3 kOe and 0.9, respectively. The high perpendicular coercivity is considered as the contribution of grains shape anisotropy. Annealing promotes the nonmagnetic Ti atoms further diffusing into the magnetic grain boundaries and segregated the magnetic grain.