TOLLEY Alfredo Juan
Highly monodisperse coreshell particles created by solid-state reactions
V. RADMILOVIC; C. OPHUS; E.A. MARQUIS; M. D. ROSSELL; A. TOLLEY; A. GAUTAM; M. ASTA; U. DAHMEN
NATURE PUBLISHING GROUP
Año: 2011 vol. 10 p. 710 - 710
The size distribution of particles, which is essential for many properties of nanomaterials, is equally important for the mechanical behaviour of the class of alloys whose strength derives from a dispersion of nanoscale precipitates. However, particle size distributions formed by solid-state precipitation are generally not well controlled. Here we demonstrate, through the example of coreshell precipitates in AlScLi alloys, an approach to forming highly monodisperse particle size distributions by simple solid-state reactions. The approach involves the use of a two-step heat treatment, whereby the core formed at high temperature provides a template for growth of the shell at lower temperature. If the core is allowed to grow to a sufficient size, the shell develops in a size focusing regime, where smaller particles grow faster than larger ones. These results suggest strategies for manipulating precipitate size distributions in similar systems through simple variations in thermal treatments.