The results allow for a greater understanding of the mechanisms underlying processes triggered by electron beams at the atomic level (image: ACS Physical Chemistry Au)

Published on 11/26/2025

Agência FAPESP* – Researchers at the Center for Development of Functional Materials (CDMF), a FAPESP Research, Innovation, and Dissemination Center (RIDC) based at the Federal University of São Carlos (UFSCar), used density functional theory calculations and ab initio molecular dynamics simulations to study the formation of silver metal nanoparticles from the application of an electron beam to four different silver tungstate surfaces. The study was published in a cover article in the journal ACS Physical Chemistry Au.

Ab initio molecular dynamics (AIMD) is an atomistic simulation technique that uses fundamental principles of quantum mechanics to analyze the temporal evolution of an atomic system.

The study had three main objectives: to reveal silver cation diffusion processes (i.e., the spontaneous movements of these ions within the material driven by the absorption of electrons from the beam), to reveal the amorphization of surfaces (i.e., the local disorganization of the crystal lattice), and to obtain a direct interpretation of the temporal evolution of silver nanocluster formation on the surfaces of β-Ag₂WO₄, one variety of silver tungstate. This material has potential applications in antibacterial agents and gas sensors, among others.

The results showed that the surfaces change when the beam is applied and allow for a broader, more fundamental understanding of the atomic-level mechanisms underlying processes triggered by electron beams. They also allow for a direct interpretation of the temporal evolution as a function of added electrons. Two of the tested surfaces, (011) and (111), are more prone to generating nanoparticles than the other two surfaces, (001) and (110), when hit by electron beams.

The work details surface patterns for creating semiconductors from the formation and evolution of silver nanoparticles using β-Ag₂WO₄.

The article “Mechanistic insights into Ag nanoparticle formation on β-Ag₂WO₄ surfaces through electron beam irradiation” can be read at pubs.acs.org/doi/10.1021/acsphyschemau.4c00062. 

* With information from the CDMF

Source: https://agencia.fapesp.br/56600