Experimental and Theoretical Investigation of Cr1-xScxN Solid Solutions for Thermoelectric Applications
(English)Manuscript (preprint) (Other academic)
We investigate the trends in mixing thermodynamics of Cr1-xScxN solid solutions in the cubic B1 structure and their electronic density of state by first-principle calculations, and thin-film synthesis of Cr1-xScxN solid solutions by reactive dc magnetron sputtering. Films with the composition Cr0.92Sc0.08N exhibit a thermoelectric power factor of about 8x10-4 Wm-1K-2at 770 K, similar to CrN. The results show that the disordered Cr1-xScxN solid solutions is thermodynamically stable in B1 solid solutions at T = 800°C rather than in the B1- L11 ordered solid solutions stable at 0 K. The calculated electronic density of state (DOS) indicates a positive bowing parameter for the electronic band gap of Cr1-xScxN solid solutions. The calculated DOS suggest possible improvement of power factor due to Sc 3d orbital delocalization on Cr 3d orbital gives decreasing electrical resistivity with retained Seebeck coefficient in Cr-rich regime, consistent with the experimentally observed high power factor for the solid solution.
Chromium nitride, Scandium nitride, Thermoelectrics, First-principles calculations, Solid solutions
IdentifiersURN: urn:nbn:se:liu:diva-117757OAI: oai:DiVA.org:liu-117757DiVA: diva2:810736