2018 Volume 42 Issue 6 Pages 127-137
We improve our model calculation for heat-assisted magnetic recording (HAMR) considering the temperature dependence of the attempt frequency. Then, the signal-to-noise ratio dependence on writing field is calculated for various calculation parameters by employing both our model calculation and the conventionally used micromagnetic calculation. The tendencies of the results of our model calculation and of the micromagnetic calculation are almost the same by this improvement. Therefore, our model calculation can be used for HAMR design. The writing process can be described using the temperature dependences of the grain magnetization reversal probability and the attempt number. If the Gilbert damping constant is small, writing is difficult since the attempt number is small. Write-error can be reduced by reducing the linear velocity, and erasure-after-write can be reduced by increasing the thermal gradient and/or the grain column number.
