Magnetostriction of electroplated TbFeCo thin films

In this work, amorphous TbFeCo films were deposited by an electroplating method. The cantilevered bilayer structures are used to investigate the magnetostriction performance of the TbFeCo films with 0.3-8.1 at% Tb. The electroplated TbFeCo films with Tb composition below 1.5 at% exhibits positive magnetostriction performance, and the films with Tb composition higher than 1.5 at% exhibits negative magnetostriction performance. The largest positive and negative magnetostriction coefficients are 52 and-148 ppm, respectively, at 7490 Oe of the external magnetic field. In addition, magnetization measurements are conducted for the positive and negative magnetostriction samples under strain. A measurable change in the magnetization curves is observed for the negative magnetostriction films. These results suggest that the negative magnetoelastic coupling of Tb-Fe and Tb-Co bonds can cause the dimensions of the films to decrease by the magnetic field, thus, the addition of the Tb element to the electroplated FeCo film results in negative magnetostriction.

Automated summary

Amorphous TbFeCo films were deposited by electroplating. The magnetostriction performance of the films was investigated using cantilevered bilayer structures. The results showed that the TbFeCo films with Tb composition below 1.5 at% exhibited positive magnetostriction, while those with Tb composition higher than 1.5 at% exhibited negative magnetostriction. It was also observed that the addition of Tb element caused a measurable change in magnetization curves for the negative magnetostriction films.