Abstract
CrSi2 powders were prepared by the solid-state reaction between chromium and silicon powders with 0.1-10.0 mass% chlorides at 650-900°C for 2h in an argon atmosphere, and the effect of addition of chlorides on the reaction temperature and particle size of the system was studied. When the atomic ratio Si/Cr in the starting materials was 2.0 in the presence of 5.0 mass% of KCl or 1.0 mass% of NaCl, the single phase of CrSi2 was obtained at 900°C, 400°C lower than without the additives. When the chloride was not added, the product formed at 1300°C exhibited particles with a grain size of about 30μm in diameter. When KCl or NaCl was added, the product formed at 900°C exhibited particles with a grain size of about 1μm in diameter. The lattice constants of the CrSi2 formed in the presence of chlorides were as follows: for 5 mass% KCl: a=0.4424 (2) nm, c=0.6360 (2) nm; for 1 mass% NaCl: a=0.4423 (2) nm, c=0.6359 (2) nm.
