作者:Z. Malik、O. Sologub、G. Giester、P. Rogl
DOI:10.1016/j.jssc.2011.08.020
日期:2011.11
The isothermal section for the system Ce-Zn-B has been established at 800 degrees C using electron microprobe analysis and X-ray powder diffraction. No ternary compounds exist and mutual solid solubilities of binary phases are negligible. In the concentration range of 10.0-10.5 at% Ce two structural modifications have been confirmed: high temperature beta Ce2Zn17 above similar to 750 degrees C with the Th2Zn17 type (R (3) over barm, a=0.90916(4) nm, c=1.3286(1)nm) and low temperature alpha CeZn7 (Ce1-xZn5+2x: x similar to 0.33) up to 750 degrees C for which we attributed the TbCu7 type (P6/mmm, a=0.52424(2), c=0.44274(1) nm). The crystal structure of CeZn7 was derived from the Rietveld refinement of X-ray powder intensities. Precise data on atom site distribution and positional parameters have been furthermore provided from X-ray single crystal refinements for two compounds, for which crystal structures hitherto have only been derived from X-ray diffraction photographs: Ce3Zn11 (Immm, a=0.45242(2)nm, b=0.88942(3)nm, c=1.34754(4)nm) and Ce3Zn22 (14(1)/amd; a=0.89363(2)nm, c=2.1804(5) nm). (C) 2011 Elsevier Inc. All rights reserved.