Effects of thin Cr film thickness on CoNiCr/Cr sputtered hard disk

The read/write properties of CoNiCr/Cr sputtered hard disks have been investigated in relation to the Cr underlayer film thickness. A high-temperature process, substrate bias, and a Cr-X target can be used to produce disks with the same coercivity and different Cr film thicknesses. It was found that B- delta , the output signal level at 5 MHz, and the recording density (D50) increased with decrease of Cr film thickness. It is suggested that the property improvements are realized due to the fine grain size, the decrease of actual CoNiCr layer thickness, and the increase of preferential growth of the c-axis of CoNiCr layer in the plane.<
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