15th Magnetic Materials Center Seminar
April 27, 2006, 9:00 am
7th floor seminar room, Sengen
Magnetic properties of nanogranular films composed of ferromagnetic and
antiferromagnetic materials
T. Furubayashi
Exchange anisotropy, which arises from exchange couplings at the interface
between ferromagnetic (FM) and antiferromagnetic (AFM) substances, was first found
in Co fine particles coated with CoO. In recent years, exchange anisotropy in FM-AFM
bilayer films has become of great importance in view of the applications to various parts
in magnetic recording and spntrinics devices, which include MR heads, MRAM,
recording media and so on.
In this talk, I report magnetic properties of granular films consisting of
nanoparticles of iron, a ferromagnetic (FM) metal, and an insulator MnF2, which is
antiferromagnetic (AFM) below the Neel temperature TN = 67 K. Magnetic properties
were examined at temperatures below and above TN by magnetization measurements
and Mossbauer spectroscopy, which was also utilized for the characterization of the
samples. Effects of exchange coupling between Fe and MnF2 on magnetic properties of
granular films are described. I would also discuss possible applications of such
FM-AFM granular films by utilizing the enhancement of magnetic anisotropy.
