Spin valve and dual spin valve heads with synthetic antiferromagnets

Analytical and micromagnetic analysis have been performed for synthetic antiferromagnet (SAF) biased single and dual spin valve heads. It is found that for a un-pinned SAF under an external field, the antiparallel axis will flop to the direction orthogonal to the field direction. Introducing a thickness differential in the SAF can help to prevent the magnetization flop in addition to the exchange pinning. Design principles for SAF biased single and dual spin valve heads are presented. An SAF biased dual spin valve head with appropriate design can have significant advantages over the single spin valve besides higher GMR values.