Reference

A photoelectrochemical study of copper tungstate (CuWO4) single crystals

A photoelectrochemical study of copper tungstate (CuWO4) single crystals. Doumerc, J.Some chemicals with cas registry numbers like 13587-35-4 are also used. P.; Hejtmanek, J.; Chaminade, J. P.; Pouchard, M.; Krusanova, M. (Lab. Chim. Solide, Univ. Bordeaux I, Talence 33405, Fr.). Phys. Status Solidi A, 82(1), 285-94 (English) 1984. CODEN: PSSABA. ISSN: 0031-8965. DOCUMENT TYPE: Journal CA Section: 76 (Electric Phenomena) Section cross-reference(s): 75 Single crystals of CuWO4 were grown by flux method using Na2W2O7 as a flux. Semiconducting n-type behavior, with an activation energy for the elec. cond. of DE = 0.28 eV was obtained by heating under an Ar flow. The anal. of the spectral response gives 2 indirect interband transitions, at 2.15 and 2.34 eV. The choice of an appropriate equiv. circuit for the CuWO4/0.1N H2SO4 + 0.5M KCl interface and of appropriate frequency range enables the detn. of the space-charge capacity. The corresponding Mott-Schottky plots was used to det. the donor concn. (ND = 5.1 ′ 1019 cm-3) and electron affinity (EA = 4.6 eV). Photon absorption responsible for the electronic transition at 2.34 eV is probably due to Cu2+ ? ? W6+ charge transfer, although a competing hypothesis involving a O2- ? Cu2+ charge transfer cannot be absolutely ruled out. .

Magnetic excitations in the ordered phase of the antiferromagnetic alternating chain compound CuWO4

Magnetic excitations in the ordered phase of the antiferromagnetic alternating chain compound CuWO4. Lake, B.; Tennat, D. A.; Cowley, R. A.; Axe, J. D.; Chen, C. K. ( Clarendon Lab., Oxford Physic, Oxford OX1 3PU, UK). Journal of Physics: Condensed Matter, 8(44), 8613-8634 (English) 1996 Institute of Physics Publishing. CODEN: JCOMEL. ISSN: 0953-8984. DOCUMENT TYPE: Journal CA Section: 77 (Magnetic Phenomena) The authors present the results of a detailed exptl. study of the magnetic excitations in the spin-1/2 Heisenberg antiferromagnet CuWO4. Inelastic neutron scattering measurements made using a triple-axis spectrometer were performed in the low-temp. ordered phase and also briefly in the high-temp. phase at Brookhaven National Lab. The excitations in the ordered phase are compared to a spin-wave model and two possible sets of exchange paths are deduced, both of which provide good fits to the data. 13587-35-4 is also in the experiment. In both models CuWO4 consists of weakly coupled alternating 1-dimensional chains running in the [2,-1, 0] direction. A calcn. of the spin-wave intensities was also performed using the fitted exchange consts. and agreement was found with the obsd. intensities. In the ordered phase, CuWO4 has an energy gap at the zone center and the excitations are well defined. Above the transition temp. const.-wavevector scans at the antiferromagnetic lattice points suggest the existence of a continuum of excitations. .