Investigation of the first-order phase transition in the Co(1-x)Mg(x)MoO(4) solid solution and discussion of the associated thermochromic behavior

Lionel Robertson (1) , Manuel Gaudon (1) , Stéphane Jobic (2) , Philippe Deniard (2) , Alain Demourgues (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 IMN - Institut des Matériaux Jean Rouxel

A series of compounds of Co(1-x)Mg(x)MoO(4) compositions has been prepared by a conventional ceramic route. The members of the whole solid solution exhibit a reversible first-order phase transition which was probed by using thermal expansion and low-temperature reflectivity techniques. Whereas the α → β transition temperature evolves linearly on warming from 435 to 200 °C with x going from 0 to 0.9, the β → α transition temperature variation falls down on cooling from -40 °C to -140 °C going from CoMoO(4) to Co(0.1)Mg(0.9)MoO(4) with an asymptotic evolution. The phase transition temperatures have been explained on the basis of a crystal polarization effect under substitution of Mg for Co. Thus, from an applicative point of view, new thermochromic pigments with tunable transition temperatures are here proposed.

Domaines: Matériaux

Lionel Robertson, Manuel Gaudon, Stéphane Jobic, Philippe Deniard, Alain Demourgues. Investigation of the first-order phase transition in the Co(1-x)Mg(x)MoO(4) solid solution and discussion of the associated thermochromic behavior. Inorganic Chemistry, 2011, 50 (7), pp.2878-2884. ⟨10.1021/ic102079f⟩. ⟨hal-00583001⟩