Anisotropic metamagnetism and magnetotransport of heavy rare-earth orthorhombic single-crystal TbAlGe

TL;DR

This study explores the complex anisotropic magnetic behavior and field-induced transitions in single-crystal TbAlGe, revealing multiple magnetic phases and their interplay with electronic topology in a topological rare-earth compound.

Contribution

It provides the first comprehensive magnetic phase diagram of TbAlGe, highlighting its rich cascade of metamagnetic transitions and potential for tunable magnetic semimetal physics.

Findings

Two antiferromagnetic transitions at 40 K and 8 K in zero field.

Multiple metamagnetic transitions only along the a-axis.

Constructed a detailed magnetic phase diagram up to 41.5 T.

Abstract

We report a comprehensive investigation of the anisotropic magnetism and magnetic field-induced transitions in single crystals of the orthorhombic system TbAlGe, a member of the topological RAlGe (R = rare-earth) family with the highest ordering temeprature in the RAlX (X = Si, Ge) series. With a single rare earth site with triangular coordination in its Cmcm orthorhombic unit cell, TbAlGe harbors complex magnetic interactions that yield two antiferromagnetic transitions at 40 K and 8 K in zero field, and a rich cascade of metamagnetic transitions that only appear for fields directed along the crystallographic a-axis. Combining electrical resistivity, magnetization and heat capacity measurements with magnetotransport experiments performed up to 41.5 T, we construct a magnetic phase diagram mapping the multiple magnetic phases of TbAlGe, and discuss the complex interplay between localized 4f magnetism and itinerant electronic topology, establishing TbAlGe as a compelling platform for exploring tunable magnetic semimetal physics.