Cyanide-bridged coordination polymers constructed from lanthanide ions and octacyanometallate building-blocks

A new series of cyanide-bridged assemblies, {KH[Ln2(2,3-pzdc)2(CH3OH)(H2O)7][M(CN)8]}·5H2O (Ln3+ = Nd, Gd, Tb, and Dy; M4+ = Mo and W), were synthesised by self-assembling lanthanide ions and octacyanometallate ions in the presence of pyrazine-2,3-dicarboxylic acid (2,3-H2pzdc). These compounds have a 3D structure in which octagon-like Ln4M4(CN)8 rings are connected through a second Ln3+ center via the carboxylate groups of one 2,3-pzdc. The resulting 1D channels are filled with K+ ions and lattice water molecules. The temperature and field dependent magnetization studies as well as ab initio calculations indicate weak ferromagnetic interactions between the Gd3+ ions within the GdMo compound whilst no magnetic interactions exist in GdW analogues. The magnetic properties of Nd3+, Tb3+ and Dy3+ compounds are strongly dominated by the magnetic anisotropy of the lanthanide ions, irrespective of the octacyanometallate building-block used

Long range magnetic order in intermediate valence CeLu alloys

The magnetic ordering in CeLu alloys has been studied using neutron diffraction, and the electronic state of the Ce has been determined using X-ray magnetic resonant scattering (XMRS). CeLu orders with the same magnetic structure as Ce Y, but the temperature dependence of the order parameter is different and the average saturated moment on the Ce sites is lower. The diffuse neutron magnetic scattering observed in other Ce alloys is not observed for CeLu, and this implies that this unusual scattering originates from the competition between exchange and dipolar interactions. The XMRS results show that the Ce in CeLu alloys has an inter- mediate valence, and the results suggest that this behaviour is due to chemical pressure

Neutron scattering from solid 3He

Multiple spin exchange leads, according to present understanding, to a variety of magnetically ordered states in solid 3He; depending on pressure and applied magnetic field. We report the status of experiments to directly determine these structures by neutron scattering. The large neutron absorption cross section, and associated sample heating, impose severe experimental demands on the design of the sample cell. We report on our proposed solution, including details of the sintered heat exchanger necessary to cool the sample,as well as the PrNi5 nuclear demagnetization stage. The use of nmr in parallel experiments to characterise growth of the solid sample within the sinter is also discussed