TEMPERATURE-DEPENDENT STRUCTURE AND ANISOTROPIC DEBYE-WALLER FACTORS OF THE DIMER COMPOUND CS3HO2BR9

The temperature-dependent structure of the dimer compound Cs3Ho2Br9 was investigated in great detail with use of the high-resolution neutron powder diffractometer D2B at ILL (Grenoble). The refinement of around 2350 nuclear reflections within the trigonal space group R3c yields largely anisotropic thermal vibrations of the Br atoms in contrast to Cs and Ho. The orientations of the thermal ellipsoids are reasonable when considering the reduced distances within the dimeric units Ho2Br3-9. Additional low temperature neutron diffraction experiments performed down to T = 7mK did not give evidence for long-range magnetic ordering. © 1991 Academic Press, Inc.