Synthesis Mechanism of an Iron–Chromium Ceramic Pigment

Abstract

The synthesis of a black Fe 2 O 3 –Cr 2 O 3 pigment has been studied to better understand the synthesis mechanism. A mechanism is proposed according to which, under the tested operating conditions, one of the starting constituents (Cr 2 O 3 ) is transferred, largely in a gas phase (after subliming), to the particle surface of the other constituent (Fe 2 O 3 ), at which it is deposited or chemisorbed, forming a layer from which it diffuses inward into the Fe 2 O 3 particles. The process stops when the composition of the resulting solid solution has become uniform.