Study of synthetic antiferromagnetic Ni81Fe19/Co90Fe10/ Ru/Co90Fe10/Ni81Fe19

A series of synthetic antiferromagnets and spin valves with synthetic antiferrimagnets as free layers were fabricated by DC magnetron sputtering. It is found that inserting a thin CO90Fe10 layer of proper thickness between Ni81Fe19 and Cu is an effective means to strengthen the antiferromagnetic coupling in the synthetic antiferrimagnet, and obtain synthetic antiferromagnets with excellent magnetic properties, i.e., higher saturation magnetic field, lower saturation magnetization value and better thermal stability. In addition, spin valves using the synthetic antiferrimagnet as a free layer have better stability.