Magnetically enhanced thermoelectrics: a comprehensive review.

Thermoelectric (TE) materials provide great potentials of recycling waste energy and solid-state cooling. The corresponding conversion efficiency has been receiving a huge attention in developing TE devices, and largely depends on the thermal and electrical transport properties. The magnetism-enhanced thermoelectrics opens a capability of making thermoelectricity a future leader in sustainable energy development and offer an intriguing platform for both fundamental physics and application prospects. In this review, state-of-the-art TE materials were summarized using magnetism point of view, providing a diagram of the charge, lattice, orbit and spin degrees of freedom. Fundamental knowledge of magnetism-induced TE effects is discussed. The underlying thermo-electro-magnetic merits were developed via the superparamagnetism- and magnetic transition-enhanced electron scattering, the field-dependent magnetoelectric coupling, and the magnon- and phonon-drag Seebeck effects. Finally, it stated several thermal-electronic and spin current-induced TE materials at the end of topics, highlighted future possible strategies for further improving ZT, as well as gave a brief outline of ongoing research challenges and open questions in this nascent field.