PREPARATION OF FE NANOCRYSTALLINE IN SIO2 BY ION-IMPLANTATION

We present a novel method, by using an ion implantation and subsequent heat treatment, to prepare Fe nanocrystalline in SiO2. The formation process of Fe granules was monitored by means of conversion electron Mossbauer spectroscopy and the size of which was determined by transmission electron microscopy. The magnetic coercivity of 100 and 70 Oe have been observed at room temperature and 80 K, respectively. A decrease of the coercivity at 80 K is probably caused by the appearance of a multidomain structure in the granules due to reducing the critical radius of single domain.