Improvement of read/write characteristics of sputtered Ba ferrite disks byadding Ta into Pt underlayers

Ba ferrite (BaM) disks with Pt and Pt-Ta underlayers were deposited by faci ng targets sputtering (FTS) apparatus. The effects of Ta addition into Pt u nderlayers on magnetic and crystallographic characteristics of BaM layers w ere investigated. The grain size of Pt-Ta underlayers was decreased with ad dition of Ta into Pt underlayers, and so the grain size of the BaM layers d eposited on them decreased. The H-c perpendicular to and S-perpendicular to of Ba ferrite layers were increased with addition of Ta into Pt underlayer s. Recording characteristics of BaM/Pt-Ta and BaM/Pt disks were investigate d. BaM/Pt-Ta disks revealed better read/write characteristics than BaM/Pt d isks due to their smaller grain size, high H-c perpendicular to of 3.4 kOe and larger S-perpendicular to. The D-50 value of 171 kFRPI was acquired in the BaM/Pt-Ta disk, which is promising for ultra-high density recording med ia.