# Hole Doping and Antiferromagnetic Correlations above the N{\'e}el temperature of the Topological Semimetal (Sr$_{1-x}$K$_x$)MnSb$_2$

## TL;DR

This study investigates hole doping effects and antiferromagnetic correlations above the Néel temperature in the topological semimetal (Sr$_{1-x}$K$_x$)MnSb$_2$, revealing persistent 2D AFM correlations and changes in magnetic ordering.

## Contribution

It provides the first detailed neutron diffraction and susceptibility analysis of K-doped SrMnSb$_2$, showing enhanced 3D AFM order and persistent 2D correlations above T_N due to hole doping.

## Key findings

- 3D C-type AFM order confirmed at T_N=305 K in K-doped sample.
- 2D AFM correlations persist above T_N up to ~560 K in parent compound.
- De Haas van Alphen oscillations indicate hole doping effects.

## Abstract

Neutron diffraction and magnetic susceptibility studies of orthorhombic single crystal {\Ksub} confirm the three dimensional (3D) C-type antiferromagnetic (AFM) ordering of the Mn$^{2+}$ moments at $T_{\rm N}=305 \pm 3$ K which is slightly higher than that of the parent SrMnSb$_2$ with $T_{\rm N}=297 \pm 3$ K. Susceptibility measurements of the K-doped and parent crystals above $T_{\rm N}$ are characteristic of 2D AFM systems. This is consistent with high temperature neutron diffraction of the parent compound that display persisting 2D AFM correlations well above $T_{\rm N}$ to at least $\sim 560$ K with no evidence of a ferromagnetic phase. Analysis of the de Haas van Alphen magnetic oscillations of the K-doped crystal is consistent with hole doping.