The compound NiCo 2 O 4 , with spinel-related structure, has been prepared by thermal decomposition of metal nitrates and its bulk structural properties examined by means of magnetic measurements, neutron diffraction, X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The results suggest a delocalised electron distribution on the octahedral sites with average oxidation states of z3.5 and z2.5 for nickel and cobalt, respectively, and lead to a cation distribution for NiCo 2 O 4 of {Ni 3z 0.1 Co 2z 0.9 } tet [Ni 3.5z 0.9 Co 2.5z 1.1 ] oct O 4 . This electronic configuration is consistent with magnetisation measurements if applied magnetic fields cause a charge redistribution on the octahedral sites to favour Co 3z and Ni 3z . The surface of NiCo 2 O 4 was examined by X-ray photoelectron spectroscopy (XPS) and found to have a different composition containing Co 2z , Co 3z , Ni 2z , Ni 3z and, probably, Ni 4z .

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The substitution of Re into Bi2O3 allows stabilization of the delta-Bi2O3 structure by additional substitution of any lanthanide ion to give, for example, phases of composition Bi12.5La1.5ReO24.5. Some of these phases have been found to show exceptionally high oxide ion conductivity at low temperatures, ca 10-3 S cm-1 at 300 degrees C. The phases show a significant structural difference from other delta-Bi2O3 phases previously reported, with interstitial anion sites displaced further from the ideal fluorite position, (1/4,1/4,1/4).

LaSrMnO 4 F has been synthesised and shown to have a staged structure in which the insertion of F atoms into the parent LaSrMnO 4 structure has occurred only in alternate (La,Sr)O rocksalt blocks.

The crystal and magnetic structures of the two related phases, Sr 2 MnGaO 5 and Ca 2 MnAlO 5 are reported. Rietveld analysis of neutron powder diffraction has revealed that both phases adopt the brownmillerite structure. Subtle differences in structure lead to the structure of Sr 2 MnGaO 5 being best described by the space group Icmm (a ~5.4888(2) A ˚, b ~16.2256(6) A ˚, c ~5.35450(2) A ˚at 2 K) while that of Ca 2 MnAlO 5 is best described by Ibm2 (a ~5.46258(9) A ˚, b ~14.9532(3) A ˚, c ~5.23135(8) A ˚at 2 K). Low temperature neutron powder diffraction data show that both phases have a simple antiferromagnetic structure. However, magnetisation data suggest a more complex picture of the magnetic order within these phases.

Our collaboration has designed, installed, and operated a compact antineutrino detector at a nuclear power station, for the purpose of monitoring the power and plutonium content of the reactor core. This paper focuses on the basic properties and performance of the detector. We describe the site, the reactor source, and the detector, and provide data that clearly show the expected antineutrino signal. Our data and experience demonstrate that it is possible to operate a simple, relatively small, antineutrino detector near a reactor, in a non-intrusive and unattended mode for months to years at a time, from outside the reactor containment, with no disruption of day-to-day operations at the reactor site. This unique real-time cooperative monitoring capability may be of interest for the International Atomic Energy Agency (IAEA) reactor safeguards program and similar regimes.

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