Design and modelling of dual spin-valve heads

Two types of dual spin-valve head structure, the anti-parallel and parallel dual spin-valve heads, were proposed. Both dual spin-valve heads are thermal noise immune due to differential voltage sensing. The transfer functions of the two dual structures were analysed and transfer curves of shielded heads were simulated using a 3-D finite element method. Results have shown that the anti-parallel dual spin-valve head exhibits greater linear dynamic range than a single spin-valve head and almost doubled output of a single spin-valve head. It also has an ideal transfer curve passing through the origin independent of the bias state of single spin-valves.