A magnoresistance effect element made up of an anti-ferromagnetic layer, a fixed magnetic layer, a non-magnetic and a free magnetic layer, laminated successively onto a base layer. The ant-ferromagnetic layer is a layer film or multiple layer film comprising Ni oxide, Co oxide, or Fe oxide as a principal component, or a mixture of these. An adhesive layer for preventing peeling due to heat generated by the flow of current is provided between the base layer and the anti-ferromagnetic layer. By providing an adhesive layer between the base layer and the ferromagnetic layer in this way, the adhesive force between the base layer and the anti-ferromagnetic layer is increased, and therefore peeling does not occur, even if there are temperature changes in the magnetoresistance effect element.

An MR head is biased to a soft adjacent layer so that deflection angles at any point around the MR element are made uniform. The SAL-biased MR head includes a SAL divided into a plurality of layers for applying a transverse bias field, insulators disposed between each of the SAL layers, an MR element in which resistance varies according to the direction and magnitude of the magnetic flux which is detected, an insulator disposed between the SAL and the MR element, and a current source for providing current to the respective SAL layers and the MR element. Thus, since a plurality of layers are used, a bias angle in the MR element becomes almost equal at any position.

In an optical recording and magnetic-head reproducing system, the reproduced output is prevented from starting to decrease, upon the length of record bits getting shorter, in the range of the bit length larger than reproducing resolution of a magnetic reproducing head. When data are recorded magneto-optically on a magnetic recording medium, the radius of curvature of arcs constituting the boundary of recorded magnetic domains is made as large as possible so that the shape of the recorded spot may be substantially rectangular. As a result, it becomes possible to improve the efficiency of magnetic reproduction, and high-output as well as high-SN-ratio reproduction at high linear recording density can be achieved.

A high sensitivity MR (GMR) sensor suitable for ultra high density magnetic recording applications. The GMR sensor has two laminated free layers each comprising two AP-coupled ferromagnetic layers separated by an antiparallel coupling (APC) layer. The two free layer structures are separated by a non-magnetic, conducting spacer layer. The sense current flowing in the layers of the sensor provide the bias field to set magnetization directions. The applied magnetic field from the magnetic disk rotates one or both of the two free laminated layers due to the moment difference of the composite AP-coupled layers that form the laminated free layers. In the initial state, with zero applied field, the GMR sensor is in the high resistance state. In the final states, with either polarity applied field, the GMR sensor is in the low resistance state. A unipolar output signal is produced as the GMR sensor switches states. The GMR sensor has no pinned layer and no antiferromagnetic layer which reduces the thickness of the MR sensor substantially.