Operando observation of magnetism in HDD writing heads by spin-polarized scanning electron microscopy.

Abstract

Operando observation using spin-polarized scanning electron microscopy (spin SEM) has been demonstrated by detecting changes in the magnetization in the writing head of a hard disk drive (HDD) during operation. A current-applying system developed for use in the sample stage of a spin SEM enables imaging of the magnetization changes in the writing head of an HDD while the writing head is activated. Focused ion beam (FIB) technology is used to fabricate electric contacts between the head terminals and the sample holder electrodes. Tungsten film is deposited by FIB technology on the insulator around the writing head to prevent electrostatic charge buildup in the insulators during SEM measurement. This system is well suited for studying the characteristics of writing heads in HDDs in an activated state.