SANS Studies of the Gallium–Indium Alloy Structure within Regular Nanopores

Abstract

Potential applications of nanolattices often require filling their empty space with eutectic metallic alloys. Due to confinement to nanolattices, the structure of phase segregates in eutectic alloys can differ from that in bulk. These problems are poorly understood now. We have used small angle neutron scattering (SANS) to study the segregation in the Ga-In alloy confined to an opal template with the regular pore network, created by a strict regularity of opal constituents in close similarity with nanolattices. We showed that SANS is a powerful tool to reveal the configuration of segregated phases within nanotemplates. The In-rich segregates were found to have specific structural features as small sizes and ordered arrangement.

Ga-In Alloy Segregation within a Porous Glass as Studied by SANS

“…The idea of comparing the scattering curves for two or more rather similar nanocomposite samples is widely used in SANS contrast matching [29,30]. The comparison of SANS intensities in an opal matrix filled with alloys of two close compositions was also applied recently in [22].…”

“…By also using Equation ( 1) for the G6 sample, and following Ref. [22], we can obtain the difference ∆I( → Q):…”

“…We also assumed, following Ref. [22], that the small additional volume ∆V of the indium-rich phase in G6 was related to an increase in the number of the indium-rich scatters or in their sizes.…”

“…Recently, we showed that small-angle neutron scattering (SANS) proved to be quite efficient in studying the size and shape of segregates in the solid Ga-In nanoalloy confined within a synthetic opal [22]. The purpose of the present work consists in the application of SANS to estimate the geometric parameters of the Ga-In segregates within a porous silica glass template.…”

“…The purpose of the present work consists in the application of SANS to estimate the geometric parameters of the Ga-In segregates within a porous silica glass template. We will use four different approaches to treat experimental SANS data: the common Guinier and extended Guinier models developed for independent scatters of arbitrary shapes [23,24], the computer simulation method based on the initial formulae for neutron scattering suggested in [22], and ordinary estimates for the wave vector at the scattering hump. We will show that the approaches predict a consistent image of the confined alloy structure.…”