Frustration-driven successive metamagnetic transitions in TbB4

TL;DR

This study investigates the complex magnetization behavior of TbB4 under high magnetic fields, revealing frustration-driven multiple metamagnetic transitions and the role of XY magnetic components in plateau phases.

Contribution

It introduces a simple spin model explaining the multi-step magnetization process driven by frustration in TbB4, supported by resonant magnetic x-ray diffraction data.

Findings

Magnetization plateau phases have large XY components.

Multiple metamagnetic transitions occur above 16 T.

Frustration is key to understanding the multi-step magnetization.

Abstract

Resonant magnetic x-ray diffraction experiments on the Shastry-Sutherland lattice TbB$_4$ were carried out under strong pulsed magnetic fields up to 30 T. TbB$_4$ exhibits a multi-step magnetization process above 16 T when magnetic fields are applied along the c-axis. We examined the intensity of the 010 magnetic reflection as a function of magnetic field and found that the magnetization plateau phases are accompanied by large XY components of magnetic moments, in contrast to normal fractional magnetization plateau phases. The magnetization was calculated using a simple spin model deduced from the above result. Finally we propose that frustration is the key to understanding the observed multi-step magnetization.