Qixu Chen

Thin film media with and without bicrystal cluster structure on glass ceramic substrates

The effect of bicrystal structure on media noise was studied experimentally. Disk samples with and without bicrystal structures have been produced on glass ceramic substrates using different Co/Cr epitaxial systems, (112~0)/(200) and (101~1)/spl par/(110). With similar magnetic properties and grain size, the former sample with the bicrystal structure has 5 dB better signal-to-noise ratio (SNR), even though the /spl delta/M curve suggests that the sample with bicrystal structure has stronger intergranular exchange coupling. The interface between NiP and Cr of the sample with bicrystals is rougher than that of the sample without bicrystals. It is suggested that the micro-roughness of the interface between NiP and Cr could affect the formation of Cr(200) texture.

Quantitative MFM study of the global and local magnetic roughness of the DC-demagnetized state of thin film media

A magnetic height-height correlation function was used to quantitatively analyze the magnetic force microscope (MFM) images of the DC-demagnetized state of two thin film media. This function provided important information about the micromagnetic features of these media, including the global magnetic roughness, the local magnetic roughness, the strength of long-range magnetostatic interaction, and the degree of local intergranular exchange coupling. These features are accountable for the noise performance of these media detected by the recording head.