Thermal microscopy of spin-valve and magnetoresistive devices

A thermal scanning microscope has been used to characterize the temperature of the different constituents of a thin film recording head under bias conditions. It shows that the temperature rise is highly concentrated in the current-biased read sensor. The results confirm calculations showing that most of the heat is dissipated through the shields, with the slider substrate acting as a heat sink. They also indicate that in SAL type AMR heads, the AMR layer is hotter than the SAL.