Insights into the local atomic and magnetic structure of MnTe using Magnetic Pair Distribution Technique

MnTe is an antiferromagnetic semiconductor with potential applications as a high-performance thermoelectric and as a platform for spintronics. The hexagonal crystal structure supports antiferromagnetic ordering of the Mn²⁺ spins below 307 K. Interestingly, robust short-range magnetic correlations called paramagnons survive well above the transition temperature and are believed to be a key ingredient for the high value of the thermoelectric figure of merit zT in doped MnTe. We report comprehensive atomic and magnetic pair distribution function (PDF) analysis of neutron total scattering data collected from pure and Na-doped MnTe in the temperature range of 2 K – 500 K. The results provide a detailed view of the local atomic and magnetic structure of MnTe in all relevant temperature regimes and help establish a more complete understanding of the excellent properties observed in this system. In particular, the magnetic PDF analysis yields valuable information about the short-range spin correlations above T_N and helps explain some unexpected magnetic behavior that has previously been observed in the low-temperature regime.