The effects of deposition conditions on microstructure and magnetic properties of TbFeCo

Transmission electron microscopy (TEM) has been employed to characterize micro/magnetic structural details of magneto-optical (MO) recording TbFeCo thin films as a function of dc-magnetron sputtering parameters using bright/dark field imaging, selected area diffraction, convergent beam electron diffraction, and Lorentz electron microscopy. It is found that the preparation conditions have a strong impact on both microstructure and magnetic properties of the films. The microstructures of the films deposited at low argon bleeding pressures (<10 mTorr) are featureless, and their magnetic domains are of the ‘‘stripe’’ type with a perpendicular anisotropy. In contrast, high argon pressures (>20 mTorr) give rise to microvoids surrounding ‘‘honeycomblike’’ networks and in-plane domains with ‘‘ripple type’’ contrast. The microstructure and magnetic domain structures are related to the films’ magnetic properties as characterized by a MO loop tracer.