Magnetic sensor including a spin valve magnetoresistance effect film

DETAILED DESCRIPTION An object of this invention, therefore, is to provide a magnetic sensor which allows accurate regulation of the read track width thereof and enjoys high sensitivity, suffers Barkhausen noise only sparingly, and excels in reliability.
Another object of this invention is to provide a magnetic head and a magnetic recording apparatus which fit for systems of high recording density by repressing such azimuth loss.
The magnetic sensor of this invention is characterized by comprising a pair of hard magnetic films magnetized inplane in directions substantially perpendicular to the direction of a signal magnetic field and substantially equal to each other, a soft magnetic film formed in the same plane as the pair of hard magnetic films and interposed between the pair of hard magnetic films and held in contact therewith or in proximity thereto, and a signal magnetic field detecting film superposed on the main surface of the soft magnetic film.
The magnetic head of this invention is characterized by comprising a reproducing head using the magnetic sensor of this invention mentioned above and a recording head provided with a pair of magnetic pole layers vertically opposed to each other across a recording gap and possessed of a recording track width equal to or smaller than the reproducing track width of the reproducing head.
The magnetic recording.
cndot.
reproducing apparatus of the present invention is characterized by comprising the magnetic recording.
cndot.
reproducing head of this invention mentioned above and a magnetic recording medium and satisfying the expression, L.
sub.
2 .
ltoreq.
L.
sub.
1 <L.
sub.
3, wherein L.
sub.
1 stands for the reproducing track width of the magnetic recording.
cndot.
reproducing head, L.
sub.
2 for the width of a track written in the magnetic recording medium by the recording head, and L.
sub.
3 for the distance between the inner ends of two tracks adjacent to the track.
As concrete examples of the signal magnetic field detecting film in the magnetic sensor of this invention, a magnetoresistance film manifesting anisotropic magnetoresistance (hereinafter referred to as "AMR film") and a ferromagnetic film (hereinafter referred to as "GMR ferromagnetic film") forming part of such magnetoresistance elements as an artificial lattice film and a spin valve film which manifest giant magneto-resistance (GMR) may be cited