Fe, Co/MgF2多層膜の電気伝導

Fe/MgF2 and Co/MgF2 multilayers were prepared by-alternate deposition in order to investigate their electric transport properties. The resistivity of the multilayers changes from metallic to semiconductive when the metal layer thickness is decreased to 45 A for Fe and 40 A for Co with a 30 A MgF2 layer thickness. For films with semiconductor-like electronic conduction, the logarithm of resistivity varies as T -1/2, which means that the tunneling process is dominant. A tunneling magnetoresistance of a few percent was found in the semiconductor-like films. The maximum MR at 15 kOe was found to be 8 % for an (Fe 15 A / MgF2 20 A) multilayer at room temperature.