Author/Authors :
Yokota, Kaori Department of Physics - Yokohama National University, Japan , Yokota, Kaori Department of Physics - Yokohama National University, Japan , Nakashima, Miki Department of Physics - Yokohama National University, Japan , Uehara, Masatomo Department of Physics - Yokohama National University, Japan , Gouchi, Jun The Institute for Solid State Physics - The University of Tokyo, Japan , Uwatoko, Yoshiya The Institute for Solid State Physics - The University of Tokyo, Japan , Umehara, Izuru Department of Physics --Yokohama National University, Japan
Abstract :
The crystal structures of praseodymium silicide (5/4), Pr5Si4, and neodymium silicide (5/4), Nd5Si4, were redetermined using high-quality single-crystal X-ray diffraction data. The previous structure reports of Pr5Si4 were only based on powder X-ray diffraction data [Smith et al. (1967[Smith, G. S., Tharp, A. G. & Johnson, W. (1967). Acta Cryst. 22, 940-943.]). Acta Cryst. 22 940–943; Yang et al. (2002b[Yang, H. F., Rao, G. H., Chu, W. G., Liu, G. Y., Ouyang, Z. W. & Liang, J. K. (2002b). J. Alloys Compd. 339, 189-194.]). J. Alloys Compd. 339, 189–194; Yang et al., (2003[Yang, H. F., Rao, G. H., Liu, G. Y., Ouyang, Z. W., Liu, W. F., Feng, X. M., Chu, W. G. & Liang, J. K. (2003). J. Alloys Compd. 263, 146-153.]). J. Alloys Compd. 263, 146–153]. On the other hand, the structure of Nd5Si4 has been determined from powder data [neutron; Cadogan et al., (2002[Cadogan, J. M., Ryan, D. H., Altounian, Z., Wang, H. B. & Swainson, I. P. (2002). J. Phys. Condens. Matter, 14, 7191-7200.]). J. Phys. Condens. Matter, 14, 7191–7200] and X-ray [Smith et al. (1967[Smith, G. S., Tharp, A. G. & Johnson, W. (1967). Acta Cryst. 22, 940-943.]). Acta Cryst. 22 940–943; Yang et al. (2002b[Yang, H. F., Rao, G. H., Chu, W. G., Liu, G. Y., Ouyang, Z. W. & Liang, J. K. (2002b). J. Alloys Compd. 339, 189-194.]). J. Alloys Compd. 339, 189–194; Yang et al., (2003[Yang, H. F., Rao, G. H., Liu, G. Y., Ouyang, Z. W., Liu, W. F., Feng, X. M., Chu, W. G. & Liang, J. K. (2003). J. Alloys Compd. 263, 146-153.]). J. Alloys Compd. 263, 146–153] and single-crystal data with isotropic atomic displacement parameters [Roger et al., (2006[Roger, J., Babizhetskyy, V., Jardin, R., Halet, J. F. & Guérin, R. (2006). J. Alloys Compd. 415, 73-84.]). J. Alloys Compd. 415, 73–84]. In addition, the anisotropic atomic displacement parameters for all atomic sites have been determined for the first time. These compounds are confirmed to have the tetragonal Zr5Si4-type structure (space group: P41212), as reported previously (Smith et al., 1967[Smith, G. S., Tharp, A. G. & Johnson, W. (1967). Acta Cryst. 22, 940-943.]). The structure is built up by distorted body-centered cubes consisting of Pr(Nd) atoms, which are linked to each other by edge-sharing to form a three-dimensional framework. This framework delimits zigzag channels in which the silicon dimers are situated.
