2012 年 36 巻 3 号 p. 150-154
Microwave-assisted magnetic recording (MAMR) has been proposed as a promising technique to achieve a higher areal recording density over 1.0 Tbit/inch2. MAMR requires a spin-torque oscillator (STO) to generate a strong, high-frequency magnetic field to induce magnetic resonance in a recording medium. The oscillation properties of STOs were previously investigated using micromagnetic models. However, simple models were used that neglected the magnetic interactions between the STO and a single-pole-type (SPT) recording head. The interactions and the magnetic field in the gap between the main pole and the trailing shield might strongly affect the oscillating characteristics. Thus, a new simulator that combines an SPT head and an STO simulator, called an integrated MAMR simulator, has been developed. The magnetic interactions between an SPT and an STO are revealed to have considerable effects on the oscillating frequency and the field strength.