Nano-magnetic probing on magnetite (110)

摘要

Spin-polarized scanning tunneling microscopy (STM) and spectroscopy (STS) allowing to image nanometer scale magnetism in real space has been successfully applied to metals like Fe [1] and Mn [2]. However, there is a high interest in probing the nano-magnetism on more complex materials with high potential for spin-valve and magnetic recording applications. A unique candidate in this respect is magnetite (Fe{sub}3O{sub}4) which is a ferrimagnetic stable oxide, abundantly found in nature and predicted to be 100% spin polarized. Particularly, the {110} facets are predominantly present in the biogenic magnetite crystals [3] thought to be involved in magnetoreception. Thus peculiar magnetic properties are expected for this orientation. Despite this, STM investigations on this surface have been performed only with a paramagnetic W tip [4,5]. These are the motivations for our study.