Magneto-optic recording materials with direct overwrite capability

The possibility of achieving direct overwrite capability in magneto-optic thin films is demonstrated. By using films having a compensation temperature tens of degrees higher than the ambient temperature, the demagnetizing field can effectively be used as a bias field for thermomagnetic writing in which writing and erasing of domains are accomplished in the absence of a magnetic field. A read-before-write scheme is proposed to facilitate the write/erase laser trigger signal to perform overwriting in real time.