An inelastic neutron scattering investigation of holmium orthoferrite.

The inelastic neutron scattering spectra recorded in this study and elsewhere provide a useful set of crystal-field (CF) energy levels for the groundJ= 6 term of Ho3+in HoFeO3. The resolution of the low-energy, temperature-dependent pseudo-quadrupole ground state splitting and magnon peaks is consistent with the self-ordering of the Ho3+sublattice atTHo∼ 8-10 K and supports earlier electron spin resonance investigations of the Ho3+magnon behaviour. Systematic analysis of the grouped singlet CF levels of Ho3: HoFeO3, in conjunction with the CF Kramers doublet levels of the neighbouring Er3+: ErFeO3, has yielded possible sets of CF parameters for the two systems.

Microgravity compatible equipment for inert gas condensation of metals during parabolic flights.

Agglomerates of nanosized metal particles can be deposited onto a variety of substrates using a custom-built, microgravity-compatible evaporation/condensation device. A metal aerosol with high solid loading is produced by rf-induction coil heating of a metal melt in a laminar inert gas flow. Valves and flow controllers operating in hypergravity and microgravity conditions allow powder samples to be prepared from such aerosols suppressing buoyancy and sedimentation effects. We present here the technical details for such a parabolic flight compatible metal aerosol source together with some initial results of nanoscale Ni agglomerates synthesized and deposited under microgravity conditions.