Published online by Cambridge University Press: 21 February 2011
Both TbCo and TbFe thin films were dc-magnetron sputtered onto carbon-coated Cu grids as well as glass substrates from a three inch mosaic target using a variety of power levels and argon pressures (PAr). The perpendicular anisotropy (Ku) displays a maximum in the range of 2.5 to 11.5 mTorr of PAr and decreased with further increases in PAr. Films deposited at low PAr (< 11.5 mTorr) exhibit a smooth and featureless microstructure. Lorentz electron microscopy images reveal the magnetic domains in them as black and white dots which are characteristic of perpendicular magnetization. On the other hand, films deposited at higher PAr (> 11.5 mTorr) exhibit a rougher surface, a high density of microvoids and in-plane magnetic domains with ripple.
A similar study was also made of the effects of deposition power on the microstructure and domains at PAr = 5 mTorr. The Ku was found to decrease with increasing power. The microstructure at 30,40 and 50 watts did not reveal any significant difference except that there was a slight increase in surface roughness with increasing power.