Effect of CrRu underlayer on the magnetic, recording, and thermal stability characteristics of CoCrPtTa thin film media

The effects of CrRu underlayers on the grain size, lattice matching, magnetic, recording and thermal stability characteristics for CoCrPtTa thin film media are presented, CrRu/sub 10/ and CrRu/sub 20/ underlayers produced about 800-960 Oe higher coercivity compared to media with a Cr underlayer. At 300 kfci recording density the CoCrPtTa/CrRu media has about 10-15% lower media noise and about 1-1.5 dB higher SNR compared to the similar media with Cr underlayer. X-ray diffraction data suggest somewhat better lattice matching between the CoCrPtTa/CrRu media due to the addition of Ru to the Cr underlayer compared to CoCrPtTa/Cr media. The CoCrPtTa/CrRu media has an average grain size of 12 nm in comparison to the average grain size of 15 nm for the CoCrPtTa/Cr media. The thin film media with CrRu/sub 10/ underlayer has smaller grain size but similar thermal stability performance compared to Cr underlayer.