PREPARATION AND PROPERTIES OF CeB//6, SmB//6, AND GdB//6.

Single crystals of CeB//6, SmB//6, and GdB//6 have been prepared by a floating-zone technique under a pressurized gas atmosphere of Ar. A zone leveling technique has been used successfully to prepare single crystals of GdB//6, a compound which peritectically decomposes. The crystals so obtained were almost stoichiometric and had a low-impurity level. The measured work functions of (001) surfaces of CeB//6 and GdB//6 are 2. 6 plus or minus 0. 1 eV, respectively. The temperature dependence of the electrical resistivity of CeB//6 resembles that of CeAl//3. The temperature dependence of the resistivity of SmB//6 single crystals is like that of a semiconductor and is similar to those reported for polycrystalline specimens.