Effect of Nanoscale Confinement on the β-α Phase Transition in Ag2Se

Vincent Leon (1) , Yang Ren (2) , Marie-Louise Saboungi (1)

1 CRMD - Centre de Recherche sur la Matière Divisée
2 APS - Advanced Photon Source [ANL]

The confinement of silver selenide was investigated using mesoporous silica. Results from x-ray diffraction and electron microscopy show that the confined material still exhibits a β to α transition similar to the one that takes place in the bulk crystalline state but with a transition temperature that depends significantly on the confinement conditions. Decreasing the pore size leads to an increase of the transition temperature, opposite to the behavior of the melting point observed in several metallic and organic materials. In the free particles, on the other hand, no size dependence is observed with particle sizes down to 4 nm.

Mots clés: Ag2Se; mesoporous silica; x-ray; confinement; phase transition; nanoparticles; synthesis

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Vincent Leon, Yang Ren, Marie-Louise Saboungi. Effect of Nanoscale Confinement on the β-α Phase Transition in Ag2Se. Journal of Applied Physics, 2008, 103 (1), pp.016105. ⟨10.1063/1.2822135⟩. ⟨hal-00192127v2⟩