The chemistry of ceramic glazes

Abstract

The development of ideas and theories concerning the structure of glazes, as one of the glassy materials, are reviewed in the general introduction. The raw materials and the manufacturing process for glazes are described (Chapter One). A number of new vanadyl(IV) dipyridylamine and tripyrldylamine complexes have been prepared, various
spectroscopic techniques are used in the investigation
of the vanadyl ion in a weak ligand field, the situation
of those found in a glaze environment (Chapter Three). In glaze recipes containing silica, potash feldspar, china clay, MO(M= Ca, Sr, Sa, Ti and Zn) and NiO, the ligand field theory is used in the elucidation of the
effect of M (in MO) on the absorption spectra and coordination behaviour of Ni(II) in glazes. The magnetic
and visible spectral results are reviewed in terms of Dietzel's idea of field strength of M and also in terms of Shteinberg's theory of glaze structure. X-ray diffraction is used for the identification of various species
that formed after the firing process of glazes (Chapter
Four). In Chapter Five, [] Mossbauer spectroscopy, supplemented by E.S.R., X-ray and visible spectral measurements are used in the investigation of iron in a glaze composition similar to that used in Chapter Four. The Mossbauer
results are used in following the influence of; M in MO
(M= Sr, Ca and Ba), oxides of titanium(IV) and vanadium(V ),
and firing conditions on the chemistry of iron. Generally
the iron(II) and iron(III) in the fired glazes are in octahedral sites although there are a range of similar, though not identical environments. A quite noticable
influence of M (in MO) on the resonance line width is seen.
In one case evidence is found for iron(IV) in an iron/vanadium glaze. E.S.R. of vanadium containing glazes indicate that vanadium is present as V02+ in a highly distorted tetragonal environment .

Date of Award	Mar 1983
Original language	English
Supervisor	William R. McWhinnie (Supervisor)