Magnetic phase diagram and transport properties of FeGe_2

TL;DR

This study investigates the magnetic phase diagram and transport properties of FeGe_2, revealing the stability of the incommensurate spin density wave phase up to high fields and observing Shubnikov-de Haas oscillations for the first time.

Contribution

The paper provides experimental evidence that the incommensurate spin density wave phase persists up to 16 T, contrary to theoretical predictions, and reports the first observation of Shubnikov-de Haas oscillations in FeGe_2.

Findings

Incommensurate spin density wave phase stable up to 16 T

Transverse magnetoresistance follows a power law without saturation

First detection of Shubnikov-de Haas oscillations in FeGe_2

Abstract

We have used resistivity measurements to study the magnetic phase diagram of the itinerant antiferromagnet FeGe_2 in the temperature range from 0.3->300 K in magnetic fields up to 16 T. In contrast to theoretical predictions, the incommensurate spin density wave phase is found to be stable at least up to 16 T, with an estimated critical field \mu _0H_c of ~ 30 T. We have also studied the low temperature magnetoresistance in the [100], [110], and [001] directions. The transverse magnetoresistance is well described by a power law for magnetic fields above 1 T with no saturation observed at high fields. We discuss our results in terms of the magnetic structure and the calculated electronic bandstructure of FeGe_2. We have also observed, for the first time in this compound, Shubnikov-de Haas oscillations in the transverse magnetoresistance with a frequency of 190 +- 10 T for a magnetic field along [001].