# Magnetotransport in Fe-intercalated \textit{T}S$_2$: the comparison between \textit{T} = Ti and Ta

## TL;DR

This study compares magnetotransport properties in Fe-intercalated TiS2 and TaS2, revealing similar sharp magnetization switching, large magnetoresistance, and the influence of superstructure defects on magnetic behavior, with implications for transition metal dichalcogenides.

## Contribution

It provides a comparative analysis of magnetotransport in 1T-Fe_xTiS2 and 2H-Fe_xTaS2, highlighting the role of superstructure defects and offering a simple model to explain observed phenomena.

## Key findings

- Similar sharp switching and large magnetoresistance in both compounds.
- Superstructure defects influence magnetic properties and switching fields.
- A simple phenomenological model explains the magnetotransport behavior.

## Abstract

Sharp magnetization switching and large magnetoresistance were previously discovered in single crystals of 2H-Fe$_x$TaS$_2$ and attributed to the Fe superstructure and its defects. We report similar sharp switching in 1T-Fe$_x$TiS$_2$ ($0.086\;{\leq}\;x\;{\leq}0.703$) and the discovery of large magnetoresistance. The switching field $H_s$ and magnetoresistance are similar to 2H-Fe$_x$TaS$_2$, with a larger than expected bowtie magnetoresistance and a sharp hysteresis loop. Despite previous reports, electron diffraction shows only the $\sqrt{3}{\times}\sqrt{3}$ superstructure in 1T-Fe$_x$TiS$_2$. The Curie and Weiss temperatures remain roughly constant below $x~\sim~1/3$ before monotonically increasing for higher x. By contrast, the switching field and magnetoresistance reach a maximum where defects in the superstructure exist, approach a minimum near perfect superstructures, and remain constant above $x~\sim~ 0.4$. Additionally, an increase in $H_s$ with annealing time is reported. Glassy behavior is shown to coexist within the ferromagnetic state in 1T-Fe$_x$TiS$_2$ for compositions between $0.1$ and $0.703$. A simple model captures the essential phenomenology and explains most similarities and differences between 1T-Fe$_x$TiS$_2$ and 2H-Fe$_x$TaS$_2$, and provides insights into other magnetically intercalated transition metal dichalcogenides.