The crystal structures of two phases in the neodymium-gold system were determined by single crystal X-ray diffractometer methods, '/.(MoKx = 0.7107 A. Nd3Au4(hR42) is trigonal, R3 (n. 148), a = 13.739(3) A, c = 6.088(2) A, Z = 6, R = 0.083 with 405 reflections, isotypic with Pu3,Pd4. Nd,7Au36(tP 106) is tetragonal, P4/nmm (n. 129), a = 15.835(4) A, c = 9.278(2) A, Z = 2, R = 0.082 with 540 reflections. The structure of Nd17Au36, which represents a new type, can be described as packing of bicapped square antiprisms with vertices occupied by five Nd and five Au atoms and centered by part of the gold atoms. This kind of polyhedron is identical to that of aluminium in the pyramidal site of the BaAl4 structure. In the Nd —Au system the phase Nd17Au36 replaces the phase given as “NdAu2”. © 1994, R. Oldenbourg Verlag. München. All rights reserved.
Crystal structure of Nd3Au4 and Nd17Au36
FORNASINI, MARIA LUISA;SACCONE, ADRIANA
1994-01-01
Abstract
The crystal structures of two phases in the neodymium-gold system were determined by single crystal X-ray diffractometer methods, '/.(MoKx = 0.7107 A. Nd3Au4(hR42) is trigonal, R3 (n. 148), a = 13.739(3) A, c = 6.088(2) A, Z = 6, R = 0.083 with 405 reflections, isotypic with Pu3,Pd4. Nd,7Au36(tP 106) is tetragonal, P4/nmm (n. 129), a = 15.835(4) A, c = 9.278(2) A, Z = 2, R = 0.082 with 540 reflections. The structure of Nd17Au36, which represents a new type, can be described as packing of bicapped square antiprisms with vertices occupied by five Nd and five Au atoms and centered by part of the gold atoms. This kind of polyhedron is identical to that of aluminium in the pyramidal site of the BaAl4 structure. In the Nd —Au system the phase Nd17Au36 replaces the phase given as “NdAu2”. © 1994, R. Oldenbourg Verlag. München. All rights reserved.
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