Magnetic Behavior of MnTe Studied With Muon Spin Relaxation

In recent years, MnTe has gained attention as a technologically relevant semiconductor with potential applications in thermoelectrics, spintronics, and more, particularly when doped with small amounts of Li or other chemical substituents. Many of the interesting behaviors exhibited by MnTe can be traced back to its magnetic properties, motivating detailed studies of the magnetism in MnTe using advanced experimental techniques.We recently performed experiments on pure and Li-doped MnTe samples using muon spin relaxation (muSR), a sensitive probe of magnetic structure and dynamics, to characterize the antiferromagnetic transition that occurs around 300 K and the magnetic dynamics across a wider temperature range. My research has focused on analyzing the muSR data using least-squares optimization and other techniques to understand the magnetic properties of pure and doped MnTe. Clear signatures of the antiferromagnetic transition are present in the data, but to our surprise, we also found anomalous relaxation of the asymmetry in the temperature range of 40K-90K. This suggests the presence of a previously unknown magnetic anomaly at low temperature. We observed this anomaly in both pure and doped MnTe, although it is somewhat reduced as the doping percentage of Li increased. Through further research, we hope to understand what structural and/or magnetic factors contributed to this observed effect.