High density magnetic recording media design and identification: susceptibility to thermal decay

TLDR

Coercivity is the primary bulk magnetic property investigated in thin‑film media. The authors performed systematic simulations of ultrahigh‑density thin‑film media, modeling di‑bit writing, subsequent thermal decay across a range of medium parameters, and predicting decay from bulk measurements. They derived a formula linking writing coercivity to VSM measurements and mapped medium performance on an anisotropy‑constant‑saturation‑magnetization plane, identifying parameter ranges for stable storage.

Abstract

Systematic simulation studies of magnetic and recording properties of thin film media at ultrahigh density have been performed with thermal effects taken into account. In the bulk magnetic property study, the focus is on coercivity. A formula for the ratio of the writing coercivity to that from the vibrating sample magnetometer (VSM) is given. The writing of di-bits and their subsequent thermal decay are simulated for a wide range of medium parameter values. From these simulations, the medium performance is mapped out on an anisotropy-constant-saturation-magnetization plane and the range of proper medium parameters suitable for stable storage determined. Ways to predict the thermal decay of written information by bulk measurements are discussed.