Advances in magnetic films of epsilon-iron oxide toward next-generation high-density recording media

Abstract

Iron oxide magnets, which are composed of the common elements iron and oxygen, are called ferrite magnets. They have diverse applications because they are chemically stable and inexpensive. Epsilon-iron oxide (ε-Fe₂O₃) is a polymorph that shows an extremely large coercive field as a magnetic oxide. It maintains its ferromagnetic ordering even when downsized to a single nano-sized scale (i.e.,<10 nm). Due to these characteristics, ε-Fe₂O₃ is highly expected to be used for high-density magnetic recording media in the big data era. Here, we describe the recent developments of magnetic films composed of metal-substituted ε-iron oxide, ε-M_xFe_2−xO₃ (M: substitution metal), toward the next-generation of magnetic media.