The influence of aliovalent impurities on transport properties of nonstoichiometric manganous sulphide

• Autorzy: Mrowec S. , Grzesik Z.
• Języki publikacji: EN

Abstrakty

EN

The influence of chromium and lithium on the manganese sulphidation kinetics has been studied as a function of temperature (973-1273 K) and sulphur activity (10(-1)-10(4)Pa) using a novel microthermogravimetric technique. It has been shown that the sulphidation of Mn-Cr and Mn-Li alloys, like that of pure manganese metal, follows strictly parabolic rate law being thus diffusion controlled. In agreement with the defect model of Mn(1-y)S it has been found that the sulphidation rate of Mn-Cr alloy is higher than that of pure manganese, the reaction rate is pressure independent and the activation energy of this process is lower. This implies that the concentration of cation vacancies in Mn(1-y)S-Cr(2)S(3) solid solution is fixed on the constant level by three-valent chromium ions substitutionally incorporated in the cation sublattice of this sulphide. In the case of Mn-Li alloy, on the other hand, the sulphidation rate is lower than that of pure manganese, and the activation energy is higher. These results can again be explained in terms of doping effect.

Słowa kluczowe

EN

sulfide; doping; sulphidation

PL

siarczan; domieszkowanie; nasiarczanie; kinetyka chemiczna

• Wydawca: Centrum Upowszechniania Nauki PAN
• Czasopismo: Bulletin of the Polish Academy of Sciences. Chemistry
• Rocznik: 2002
• Tom: Vol. 50, No. 1
• Strony: 37--49
• Opis fizyczny: Bibliogr. 22 poz.

Twórcy

autor

Mrowec S.

autor

Grzesik Z.

• University of Mining and Metallurgy, Faculty of Materials Science and Ceramic, Department of Solid State Chemistry, al. Mickiewicza 30, 30-059 Kraków, Poland (Wydział Inżynierii Materiałowej i Ceramiki, AGH)