MAGNETIC RESISTANCE EFFECT ELEMENT

摘要

PROBLEM TO BE SOLVED: To make a magnetic resistance effect element effective as a magnetic sensor or the like that has a high magnetic sensitivity and detects a weak magnetic field, by performing the epitaxial growth of a ferromagnetic oxide thin film on an oxide substrate with an atom layer level step on the surface and utilizing a crystal grain boundary that is introduced in that case as a magnetic resistance generation part. SOLUTION: The line of iron atom and molybdenum atom is shifted directly above the atom layer step of a substrate in an Sr2FeMoO6 thin film that is subjected to epitaxial growth on <111> face of SrTiO3. On the boundary surface, the connection chain of (-Fe-O-Mo-O-) in ideal crystal structure is cut, thus resulting in Fe-O-Fe or Mo-O-Mo arrangement. A resistance measurement pattern is formed for the thin film by the photolithography so that the direction of current is vertical to a substrate step, thus inverting the directions of magnetization at the boundary part. Since the conduction electron spin in the ferromagnetic has an extremely large polarization rate, the electrical resistance at the boundary part is maximized in this state.