FC-MAMR – Flux Control – Microwave-Assisted Magnetic Recording. A Toshiba technology. Microwaves are generated by a Spin Torque Oscillator (STO) positioned next to a disk drive write head. The STO used includes a microwave Field Generation Layer (FGL) and a Spin Injection Layer (SIL). FC-MAMR is an approach technology for full MAMR. It involves reversing the direction of the STO and so providing a 20 per cent areal density gain to PMR technology.