Computational nano-materials design for colossal thermoelectric-cooling power by adiabatic spin-entropy expansion in nano-superstructures

In addition to the conventional Peltier effect, we propose a new class of thermoelectric-cooling mechanism based on the adiabatic spin-entropy expansion in a quasi-one-dimensional nano-superstructure by injecting the spin current from the ferromagnetic metal to paramagnetic one. The spin-entropy expansion mechanism dominates and enhances the thermoelectric-cooling power dramatically in current perpendicular to plane-giant magneto-resistance (CPP-GMR) Co/Au nano-interface. Based upon the spin-entropy expansion mechanism, we design the new thermoelectric-cooling nano-superstructures using the newly designed half-Heusler ferromagnets NiMnSi (T-C = 1050 K) and self-organized quasi-one-dimensional Konbu-phase (Zn,Cr)Te with very high blocking temperature (> 1000 K) by spinodal nano-decomposition.