Electrically Tunable Thin Film Magnetic Core Using Synthetic Antiferromagnet Structure

We demonstrate an electrically tunable thin-film magnetic core using a synthetic antiferromagnet (SAF) structure. It consists of two ferromagnetic layers antiferromagnetically coupled together through an exchange coupling layer. Variation of susceptibility is achieved by leading a current through the structure. A tuning range (relative change in susceptibility) of 35% can be achieved at 800 Hz by using patterned NiFe(12 nm)/Ru(0.7 nm)/NiFe(12 nm) SAF structures. Different patterns of test samples are designed to investigate the influence on the tuning performance.