(La, Ba)MnO3 BASED ROOM TEMPERATURE EXTRAORDINARY MAGNETO-RESISTANCE MATERIAL

摘要

PROBLEM TO BE SOLVED: To form material which has extraordinary magneto-resistance effect at a room temperature by making perovskite type oxide a thin film and controlling magnetism. SOLUTION: This room temperature extraordinary magneto-resistance effect material is constituted of a manganese oxide thin film which is formed on a substrate by using epitaxial growth and has a perovskite type structure shown by a general formula (La1-xBax)MnO3 (where 0.02<=x<=0.25). The thin film is adjusted thick enough to be affected by tensile strain and not subjected to heat treatment while film formation is performed. The peak of magneto-resistance ratio exists at a temperature equal to or higher than 0 deg.C. The peak value is at least 40% under an applied magnetic field of 0.8 T. The substrate is composed of material having a lattice constant greater than that in the state of equilibrium of bulk material of manganese oxide having perovskite type structure shown by (La1-xBax)MnO3 (where 0.02<=x<=0.25) such as SrTiO3 single crystal and Sr1-yBayTiO3 (where 0