CRYSTALLINE TERNARY CERAMIC PRECURSORS

摘要

A method of forming M<SUB>n+1</SUB>AX<SUB>n</SUB>, where M is an early transition metal (such as Ti) or mixtures thereof, A is a group III or IV element (such as Si) or mixtures thereof and X is C, N or mixtures thereof, the method comprising the steps of providing a precursor of formula M<SUB>n+1</SUB>AX<SUB>n</SUB> and reacting the M<SUB>n+1</SUB>X<SUB>n</SUB> with A to provide M<SUB>n+1</SUB>AX<SUB>n</SUB>. The M<SUB>n+1</SUB>X<SUB>n</SUB> may be ordered and/or twinned (eg by mechanical alloying, thermal treatment etc. prior to reacting with A, ordered and/or twinned during its formation from M and X. A may be present during the formation of M<SUB>n+1</SUB>X<SUB>n</SUB> from M and X or during the ordering and/or twinning of disordered M<SUB>n+1</SUB>X<SUB>n</SUB>. The M<SUB>n+1 </SUB>AX<SUB>n</SUB> produced is substantially free from MX and or other residual phases.