Abstract
Cu0:96Fe0:04O1-delta nanocrystalline films were fabricated using reactive sputtering at different oxygen partial pressures (P-O2). The electrical transport properties of the films were measured in a broad temperature range (10-300 K) under magnetic fields of up to 5 T. Anomalous Hall effect (AHE) of up to 0.4 mu Omega cm was observed at 10 K and decreased to 0.2 mu Omega cm at 300 K. The characteristic AHE clearly indicated the existence of ferromagnetism in these materials. The AHE weakened as PO2 increased because the increasing PO2 reduced the fraction of Fe2+ ions, and consequently weakened the double exchange coupling between Fe2+-O2--Cu2+ in the materials. (C) 2011 The Japan Society of Applied Physics