Thermoelectricproperties of Mn-doped Ru₂Si₃

L. Ivanenko¹, A. Filonov¹, V. Shaposhnikov^1,4, A. Krivosheev¹, G. Behr², D. Souptel²,

J. Schumann², H.Vinzelberg², S.Paschen³, V. Borisenko¹

¹BelarusianState University of Informatics and Radioelectronics, P. Browka 6, 220013Minsk, Belarus

²LeibnizInstitute for Solid State and Materials Research Dresden, PF 27 01 16, D-01171Dresden, Germany

³MaxPlanck Institute for Chemical Physics of Solids, Nöthnitzer Str.40,D-01187 Dresden, Germany

⁴Department of Physics, University ofAveiro, 3810-193 Aveiro, Portugal

Pureand Mn-doped single crystals of ruthenium silicide Ru₂Si₃have been grown by floating zone technique with radiation heating in order toinvestigate the thermoelectric efficiency of this compound. Electricalresistivity, Hall effect, Seebeck coefficient and thermal conductivity of thecrystals were measured across a wide range of temperatures. Undopedcrystals show in the thermoelectric power both types of conductivity. TheSeebeck coefficient of Ru_1-xMn_xSi_1.5 is positive at alltemperature range and reaches the maximum value of S=450 mV/K at about 500 K. Theroom temperature value of S=300 mV/K is twice higher in magnitudethan the corresponding value for the undoped Ru₂Si₃. Thecarrier concentration in the 1% Mn-dopedsamples is about 10¹⁸cm^‑3at room temperature and the Hall mobility is about 20 cm²/V×s. Comparisonwith the undoped Ru₂Si₃ shows a two-fold increase ofmobility as the result of doping.

Theoretical calculation of the charge carrier mobilityis based on the effective masses, which are estimated from the ab initioelectronic band structure and classical scattering mechanisms. The anisotropy was found for both types of carriers.The mobility as well as thermoelectric properties estimated in the widetemperature range confirmed the experimental data for both doped and undoped Ru₂Si₃ crystals.