Preparation and magnetic properties of TbFeCo on the porous alumina template

A self-ordered hexagonal array of nanopores has been fabricated by anodizing a thin film of Al on glass and subsequent the magnetic properties of TbFeCo on this templates were studied.We carried out anodic oxidation of a sputtered Al film at the anodic voltage in the range of 10-30V and temperature in the range of 5-40℃,and found that the density of the nanohole arrays increased with the decrease in anodization voltage and temperature.On the other hand,hole diameter decreased with the decrease in anodic voltage and temperature.Then TbFeCo is deposited onto this porous array by sputtering with a thickness of around 90nm and subsequently overcoated with 10nm SiN for the protection from surface oxidation.The TbFeCo deposited on this porous layer shows complete perpendicular anisotropy.The coercivity increased with the decrease in hole diameter.The coercivity of the TbFeCo deposited on the porous array with a mean hole diameter of around 15nm is 4.5×105A/m and larger than on the glass,but the squareness ratio gets poorer than on the glass.It seem that there were no significant changes in Ms.