Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles

Using compressive mechanical forces, such as pressure,to inducecrystallographic phase transitions and mesostructural changes whilemodulating material properties in nanoparticles (NPs) is a uniqueway to discover new phase behaviors, create novel nanostructures,and study emerging properties that are difficult to achieve underconventional conditions. In recent decades, NPs of a plethora of chemicalcompositions, sizes, shapes, surface ligands, and self-assembled mesostructureshave been studied under pressure by in-situ scattering and/or spectroscopytechniques. As a result, the fundamental knowledge of pressure-structure-propertyrelationships has been significantly improved, leading to a betterunderstanding of the design guidelines for nanomaterial synthesis.In the present review, we discuss experimental progress in NP high-pressureresearch conducted primarily over roughly the past four years on semiconductorNPs, metal and metal oxide NPs, and perovskite NPs. We focus on thepressure-induced behaviors of NPs at both the atomic- and mesoscales,inorganic NP property changes upon compression, and the structuraland property transitions of perovskite NPs under pressure. We furtherdiscuss in depth progress on molecular modeling, including simulationsof ligand behavior, phase-change chalcogenides, layered transitionmetal dichalcogenides, boron nitride, and inorganic and hybrid organic-inorganicperovskites NPs. These models now provide both mechanistic explanationsof experimental observations and predictive guidelines for futureexperimental design. We conclude with a summary and our insights onfuture directions for exploration of nanomaterial phase transition,coupling, growth, and nanoelectronic and photonic properties.

Automated summary

Using compressive mechanical forces to induce crystallographic phase transitions and mesostructural changes in nanoparticles has provided unique insights into new phase behaviors and novel nanostructures. Recent research has improved our understanding of the pressure-structure-property relationships and led to better design guidelines for nanomaterial synthesis. Molecular modeling has further contributed to mechanistic explanations and predictive guidelines for future experiments.