Strain-induced enhancement of coercivity in amorphous TbFeCo films

TL;DR

This study demonstrates that reducing the size of amorphous TbFeCo films significantly increases their coercivity due to strain relaxation, highlighting potential for nanoscale magnetic device applications.

Contribution

It reveals the size-dependent coercivity enhancement in amorphous TbFeCo films caused by strain relaxation, a novel insight for magnetic property tuning.

Findings

Coercivity increases up to 300% with reduced device width.

Large coercivity enhancement linked to film stress relaxation.

Strain and dimensionality influence coercivity in TbFeCo films.

Abstract

We report a strong size dependence of coercivity in amorphous ferrimagnetic TbFeCo films. The as-deposited film exhibited a low saturation magnetization (Ms=100 emu/cc) and a high perpendicular anisotropy (Ku=10^6 erg/cc). Hall-bar devices were fabricated for characterizing the magneto-transport behaviors. A significant increase in coercivity (up to 300 %) was observed at room temperature as the width of Hall bar was reduced. The large coercivity enhancement was attributed to the relaxation of film stress. The effect of strain and dimensionality on the coercivity in TbFeCo makes it attractive for tunable coercivity and the magnetization reversal in future nanoscale devices.