Tunnel magnetoresistance (TMR) in ferromagnetic metalinsulator granular films

We review the recently discovered tunnel-type giant magnetoresistance (GMR) in ferromagnetic metal-insulator granular thin films, which is the magneto resistance (MR) associated with the spin-dependent tunneling between two fe rromagnetic metal particles. The theoretical and experimental results inclu ding electrical resistivity, magnetoresistance and their temperature depend ence are described. Limitations to the applications of the ferromagnetic me tal-insulator granular films are also discussed. Additionally, a brief surv ey of another two magnetic properties, high- frequency property and giant H all effect: (GHE) associated strongly with the granular structures is also presented.