(Fe,Co)-P thin films prepared with a reactive evaporation method

Magnetic properties of (Fe,Co)₂P thin films prepared with the thermal-activated reactive evaporation method were investigated for recording media application. Above 300 degrees C, metals (Fe,Co) and phosphorus react to form M₂P. The coercive forces of these films had a maximum value of 1.3 kOe at 10% Co concentration, and the saturation magnetization increased with the increase in Co concentration. Annealing at 500 degrees C for 30 min increased the coercive force of the films up to two times. The reproduced output from the isolated magnetization transitions of a (Fe,Co)-P-film rigid disk with a ring head showed waveforms of typical longitudinal recording. A recording density of 62 kfrpi at D₅₀ was attained with a disk medium of about an 800-AA-thick layer.