THE ROLE OF INTERMEDIATE CALCIUM ALUMINATE PHASES IN SOLID STATE SYNTHESIS OF MAYENITE (<font>Ca</font>₁₂<font>Al</font>₁₄<font>O</font>₃₃)

Abstract

Structural transformations during the synthesis of mayenite ( Ca 12 Al 14 O 33 ) were investigated. The samples were prepared by a solid–state reaction and the transformations were researched by means of XRD, Rietveld analysis, SEM, and Raman spectroscopy. The three key phases ( CaAl 2 O 4 , Ca 3 Al 2 O 6 , Ca 5 Al 6 O 14 ) were identified and their role in the mayenite formation was assigned. The optimal low temperature pathway of the mayenite synthesis involving Ca 5 Al 6 O 14 intermediate was proposed.