Surface stabilization determines a classical versus non-classical nucleation pathway during particle formation

Abstract

Particle formation can occur by way of a classical or non-classical nucleation pathway. We show that during the bottom-up synthesis of cobalt particles the degree of particle surface stabilization determines the formation pathway. Without additives, young cobalt particles are liquid because of the size-dependent melting point depression, and crystallization starts only after growth by coalescence, in accord to a non-classical pathway. Addition of surfactants during synthesis leads to particle surface stabilization and, thus, an elevated melting point such that a crystalline nucleus is formed in a classical pathway.