Modification of polycrystalline nanodiamonds by using periodic magnetic field enhanced hydrogen plasma and the application on nanogrinding of thin film magnetic head

Polycrystalline nanodiamonds (NDs) derived from shock wave synthesis exhibits serious agglomeration in non-polar medium such as clean oil. Here we report an efficient new approach to modify the NDs by exposing the nanoparticles to periodic magnetic field (PMF) enhanced hydrogen plasma in the gas phase. The modification treatment transforms oxygenated groups on the NDs surface into CH terminations. The evolution of polycrystalline NDs has been carefully characterized by FTIR, Raman and XRD analysis and the enhancement mechanism of PMF was discussed. After this treatment, well-dispersed and stable suspensions of diamond nanoparticles in clean oil with average diameter of 74.7 nm can be obtained. Subsequent nanogrinding of thin-film magnetic heads (TFH) validates their dispersion behavior. A smooth substrate (Ra ∼ 0.387 nm) surface and a planar recording surface (PTR ∼ 0.048 nm) were achieved.

By modifying diamond nanoparticles with PMF enhanced H2 plasma in the gas phase, well-dispersed and stable suspensions of polycrystalline NDs in clean oil medium can be prepared. As can be seen from the SEM image, most of the particles are basically spherical or near spherical and the size distribution is approximately 80–100 nm. The adhesion covered diamond nanoparticles is residual clean oil, which cannot be volatilized.Figure optionsDownload as PowerPoint slideHighlights
► Modification of polycrystalline nanodiamonds by using PMF enhanced H2 plasma.
► The enhancement mechanism of PMF on H2 plasma modification was clarified.
► Well-dispersed nanodiamonds in clean oil have been prepared.
► The application on nanogrinding of thin film magnetic head was testified.
► A smooth substrate (Ra ∼ 0.387 nm, PTR ∼ 0.048 nm) was achieved.