Magnetic and electrical properties of Fe–MoOx (2⩽x⩽3) granular thin films

Abstract We have synthesized for the first time the new granular system Fe–MoOx (2⩽x⩽3) by using a sputtering technique. The magnetic measurements reveal that the granular films exhibit superparamagnetism and the interface of the iron granules is oxidized partially. Negative magnetoresistance is observed at low temperatures for the Fe–MoOx (x∼2) granular thin films synthesized under reducing atmosphere. The behavior of the negative magnetoresistance strongly depends on the ratio of the Fe to the MoOx. It is suggested that the electronic conduction is mainly due to the spin-dependent tunneling through the oxidized interface between the granules and the matrix.