X-ray analysis of solid solutions of ferric oxide in mullite

Influence of TiO2, Fe2O3 and Na2O on the structural changes in fused mullite

“…Information on the maximum amount of oxide which may dissolve in the mullite at a certain temperature is contradictory, not only from different authors but also within the work of the same authors carried out in different years [4,5,7,8]. According to [5] the maximum solubility of titanium and iron oxides in mullite at 1400~ was 1.5 and 3%* respectively; according to [8] the same authors state that mullite dissolves 2-2.5% TiO2 at 1400~ 6% Fe203 at 1300~ and 8-9% Fe203 at 1400~ According to [7] the maximum solubility of Fe203 is 6.5% at 1450~…”

“…Mullite can form a rather wide range of solid solutions with different oxides: AI~O~, Fe203, Ti02, Cr203, and B203 [1][2][3][4][5][6][7][8][9][10][11][12]. However, relevant data in this case are contradictory.…”

“…In all cases the authors mention the increase in the parameters of the unit cell with the solution of Fe2Os and Ti02; mention is also made of the preferential grwoth of the b parameter [3,6] and c parameter [4].…”

Variable-composition fused mullite obtained by induction melting in a cold crucible

“…* The intensities for all the strongest diffraction reflections of mullite and all kinds of its composition (1.5 -< ~-< 2) were calculated f r o m the refined [9] crystallographic model of mullite, generalzed for the case of random ~t by Razumovskii et al [10]. To exclude the dependence of the m e a s u r ement results on the conditions under which the x -r a y diffraction photographs were taken, we used not the intensities but their ratio.…”