Structural studies by electron and X-ray diffraction of the disordered phases II': (Sn_1−x Tb _x )Tb₄Rh₆Sn₁₈ and (Sn_1−x Dy _x )Dy₄Os₆Sn₁₈

Abstract

Snl_xTbx)Tb4Rh6Sn18 and (Snl_xDyx)Dy4OsrSnls belong to a large stannide series where there exist two chemical formulae: SnM3M~Sn~2 (phase I and I') and SnM4M~Sn~8 (phase II and II'), and four structures: I, I', II and II'. That of phase II' appeared to be cubic (a = 13.7/~ and space group Fm3m) while the structure of phase II is tetragonal (a = 13-7, c ~-27.4A and space group I4~/acd). Phase II' of the * Present address: KFK, ITP Postfach 3640, D-7500 Karlsruhe, Federal Republic of Germany. 0108-7681/87/010076-08501.50 streaks. Crystal data for (Snl_xTb,,)Tb4Rh6Snl8, x = 1: M, = 3548.5, disordered microtwinned tetra~onal, 14~/acd, a = 13.772 (2)A, c=2a, V= 5224.2 A, Z= 8, D,, = 9.02 gcm -3, Ag Ka, graphite monochromator, /z = 175-9 cm -t, F(000) = 11 960, T= ambient. AbstractElectron-density distribution of a nitrite ion was calculated by the ab initio molecular-orbital method using STO-3G, STO-6G, MIDI4 and MIDI4* basis sets. The N-O bonding peak, which was observed in the experimental deformation density of LiNO2.H20, could be reproduced only by using the MIDI4* basis set. This indicates the importance of polarization functions in the study of charge distribution.

Crystal Structure, Specific Heat, and119Sn Mössbauer Spectroscopy of CeRu4Sn6: A Ternary Stannide with Condensed, Distorted RuSn6Octahedra

“…Several tin-rich rare-earth ruthenium tin alloys have been prepared in the 1980s (13-16) when searching for new superconducting materials. These alloys have structures related to Tb Rh Sn (17,18). With yttrium the metallic stannide YRu Sn (19) has recently been reported.…”

Highly Anisotropic Gap Function in a Nonmagnetic Superconductor Y5Rh6Sn18

“…The tetragonal structure can be considered as a quasi-cubic structure, which is composed of two blocks of a cubic structure. 8,9) Single crystals of Y 5 have the typical dimensions of 3 3 2 mm. The detailed * E-mail address: n-kase@phys.aoyama.ac.jp growth condition is described in the previous report.…”

Superconducting Gap Structure of the Cage Compound Sc5Rh6Sn18

“…Ternary stannides R 5 Rh 6 Sn 18 (R = Sc, Y, Lu), which can also be classified as the cage compounds, exhibit superconductivity with the transition temperature T c = 5 K (Sc), 3 K (Y), and 4 K (Lu) [5]. These compounds have a tetragonal structure with the space group I4 1 /acd and Z = 8, where R occupies two sites of different symmetry.…”

“…These compounds have a tetragonal structure with the space group I4 1 /acd and Z = 8, where R occupies two sites of different symmetry. One of the R site is surrounded by the Rh 6 Sn 12 cage that forms a f cc lattice in its structure [6]. The tetragonal unit cell consists of two cubic blocks, forming a distinct superlattice along the c-axis.…”