MAGNETIC TUNNEL JUNCTION ELEMENT AND READING SENSOR

摘要

PROBLEM TO BE SOLVED: To provide MTJ elements which are reduced in the magnetic moment of the nets of ferromagnetic layers so as to controllably decrease the magnetostatic interactions between the ferromagnetic layers within the single element or between the MTJ elements without much complication in the formation of the MTJ elements. SOLUTION: The improved magnetic tunnel junction (MTJ element) useful within the magnetic record reading head or magnetic memory storage cell consists of the two ferromagnetic layers, i.e., the 'hard' or 'stationary' ferromagnetic layer 118 and the detection or 'free' ferromagnetic layer 132, which are separated by a thin insulation tunnel layer 120. Each of the respective ferromagnetic layers is multiple layers consisting of two thinner ferromagnetic films which are antiferromagnetically bonded across the thin antiferromagnetic bond film 116 to each other. The antiferromagnetic bond film is so selected with respect to its material compsn. and thickness that the magnetic moments 133 of the two ferromagnetic films holding itself in the absence of external magnetic first are aligned antiparallel with each other.