塩化物添加のもとでの金属クロムとケイ素粉末の固相反応によるCrSi_2の合成  [in Japanese] Preparation of CrSi_2 Powders by Solid-State Reaction between Chromium and Silicon Powders with Addition of Chlorides  [in Japanese]

CrSi_2 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 CrSi_2 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 30 μm in diameter. When KCl or NaCl was added, the product formed at 900°C exhibited particles with a grain size of about 1 μm in diameter. The lattice constants of the CrSi_2 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=0.4424(2)nm, c=0.6359(2)nm.