Pigments for the 21st century
thesisposted on 17.06.2013, 13:30 by Christopher J. Kirk
Materials with potential for high temperature inorganic pigment applications (e.g. ceramics) have been synthesised using solid state methods and characterised using powder X-ray and neutron diffraction, magic angle spinning NMR, Mossbauer spectroscopy, UVNis spectroscopy and colour measurement techniques. A number of compounds containing tin (H) and niobium (V) have been modified and doped with various constituents to tailor and widen the colour properties of the bright yellow parent phases. The dark yellow (L*(91.28), a*(13.74), b*(54.76) tin niobium oxide pyrochlores have been re-characterised using neutron diffraction techniques. These materials exhibit both cation and anion disorder caused by a stereoactive lone pair on the tin (H) metal centres. Solid state NMR and Mossbauer studies have shown the presence of tin (IV) on a symmetric site within the primary phase of the pure oxide pyrochlore and methods have been investigated to minimise the tin (H) disproportion method from where the tin (IV) is derived....