Magnetic Frameworks and Non-Magnetic Dopants: A Novel Strategy for Enhancing Thermoelectric Efficiency in Manganese Telluride - Mechanistic Insights into Charge Carrier Dynamics and Phonon Transport.

Manganese Telluride (MnTe) exhibits substantial promise for thermoelectric applications; however, its efficiency is hindered by suboptimal electrical and thermal characteristics. This study investigates the incorporation of non-magnetic zinc into the magnetic framework of MnTe, leading to an enhanced thermoelectric figure of merit by optimizing the interplay between electrical and thermal transport properties through several mechanisms: i) enhanced weighted mobility and reduced effective mass facilitate superior charge carrier dynamics, stemming from modifications to the electronic band structure and a concomitant reduction in spin-disorder scattering, particularly near the Néel transition temperature; ii) suppression of the MnTe₂ secondary phase effectively minimizes impurity scattering; iii) favorable interactions between charge carriers and phonons facilitate acoustic phonons to dominate scattering mechanisms at elevated temperatures; iv) reduced lattice thermal conductivity, attributed to three-phonon scattering, lattice anharmonicity, and effective spin-phonon coupling, further enhances overall thermoelectric efficiency. Beyond the thermoelectric aspects, this work elucidates the emergence of weak anti-localization, multichannel Kondo effects, and magneto-elastic coupling phenomena in MnTe-based materials. These findings pave the way for novel explorations in magnetic strategies for thermoelectrics, transitioning the emphasis from the conventional approach of introducing magnetic impurities in non-magnetic compounds to the enhancement of properties in inherently magnetic materials via non-magnetic dopants.