Effect of Nanoscale Confinement on the \beta-\alpha Phase Transition in Ag2Se

TL;DR

This study investigates how nanoscale confinement within mesoporous silica affects the eta-lpha phase transition in Ag2Se, revealing that pore size influences transition temperature contrary to melting point trends.

Contribution

It demonstrates that nanoscale confinement alters the phase transition temperature in Ag2Se, with smaller pores increasing the transition temperature, a novel finding compared to bulk behavior.

Findings

Transition temperature depends on pore size in confined Ag2Se.

No size dependence observed in free particles down to 4 nm.

Confinement shifts phase transition behavior contrary to melting point trends.

Abstract

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 \beta to \alpha 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.