%0 Journal Article
%A Prymak, Oleg
%A Grasmik, Viktoria
%A Loza, Kateryna
%A Heggen, Marc
%A Epple, Matthias
%T Temperature-Induced Stress Relaxation in Alloyed Silver–Gold Nanoparticles (7–8 nm) by in Situ X-ray Powder Diffraction
%J Crystal growth & design
%V 20
%N 1
%@ 1528-7505
%C Washington, DC
%I ACS Publ.
%M FZJ-2020-02830
%P 107 - 115
%D 2020
%X Alloyed silver–gold nanoparticles (spherical, 8 nm) were wet-chemically prepared by reduction with sodium citrate/tannic acid and colloidally stabilized by poly(N-vinylpyrrolidone) (PVP), in steps of 10 atom %, including pure silver nanoparticles (35 nm) and pure gold nanoparticles (7 nm). The nanoparticles were subjected to in situ X-ray powder diffraction up to 850 °C to induce internal stress relaxation and recrystallization. The stress-induced negative deviation from Vegard’s rule that was present in the original alloyed nanoparticles vanished between 150 and 250 °C, indicating the internal healing of defects. Simultaneously, a discontinuous increase in the crystallite size and a drop in the microstrain were observed. After heating to 850 °C, the original gradient structure (silver-rich shell, gold-rich core) had changed to a homogeneous elemental distribution as shown by high-angle annular dark-field scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy (STEM/EDX). Thus, there is a considerable mobility of the metal atoms inside the nanoparticles that starts as low as 150 °C.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000506088200016
%R 10.1021/acs.cgd.9b00728
%U https://juser.fz-juelich.de/record/878394