FePt as Read Sensor Hard Bias Material

A low temperature chemical ordering approach was presented for L1₀ phase FePt alloy´s application in read sensor hard bias. We show that platinum seed and cap layers together can help the iron-rich FePt layer to achieve A1 to L1₀ phase transformation at temperatures as low as 300 ^°C. For platinum-rich FePt alloy iron seed and cap layers are effective in promoting its phase transformation. Element cap and seed together are more effective to obtain high coercivity than either of them alone. In order to implement FePt permanent magnet in transducer product, new thermal processes and sequences are needed.