Synthesis, structural characterization and magnetic properies of Gd14W4O33-xNy (0≤x≤17, 0≤y≤9), a new fluorite-related oxynitride
1996 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, Vol. 240, no 1-2, 60-69 p.Article in journal (Refereed) Published
A series of crystalline Cd-W oxides. with Gd:W ratios spanning the values 0.1-3.5. has heen prepared and treated with a flow of NH3(g) in the temperature range 700-1100 oC. Besides the previously reported formation of GdWO3N and Gd2WO3N2. the following new results were obtained: (I) cubic Gd0.1WO3 upon ammonolysis forms an (oxy)nitride Gd0.1x W(O. N) with an f.c.c lattice; (ii) the previously described Gd2WO3N2 exhibits a solid solubility range Gd3-xW1+x(O.N)y with, approximately, 0≤x≤1; (iii) ammonolysis of Gd14W4O33 yields an oxynitride, the composition of which varies with the synthesis temperature according to Gd14W4O33-xNy (0≤x≤17±2, 0≤y≤9±2). All strong diffraction lines, including those of the pure oxide (x =y= 0), can be indexed with a body-centred monoclinic unit cell derived from that of fluorite. For Gd14W4O33 the cell parameters are a = 5.3592(11), b = 3.7295(7), c = 3.8636(8), β = 92.170(2)o and V = 77.17 Å3. However, strong superstructure rereflections in the electron diffraction patterns indicate that the true unit cell is considerably larger. A partial structur determination of Gd14W4O33-xNy has been carried out by the Rierveld method. Magnetic susceptibility measurements in the temperature interval 15-300 K show a Curie-Weiss behaviour for Gd14W4O33-xNy with μeff = 8.08±0.06 Bohr magnetons per Gd3+ and θ = −12.4±1.1 K for all compositions.
Place, publisher, year, edition, pages
1996. Vol. 240, no 1-2, 60-69 p.
Gd-W oxynitrides; Ammonolysis; Rietveld refinement; Electron diffraction; Magnetic susceptibility
IdentifiersURN: urn:nbn:se:liu:diva-54188DOI: 10.1016/0925-8388(96)02325-0OAI: oai:DiVA.org:liu-54188DiVA: diva2:300853