TY  - JOUR
AU  - Prymak, Oleg
AU  - Grasmik, Viktoria
AU  - Loza, Kateryna
AU  - Heggen, Marc
AU  - Epple, Matthias
TI  - Temperature-Induced Stress Relaxation in Alloyed Silver–Gold Nanoparticles (7–8 nm) by in Situ X-ray Powder Diffraction
JO  - Crystal growth & design
VL  - 20
IS  - 1
SN  - 1528-7505
CY  - Washington, DC
PB  - ACS Publ.
M1  - FZJ-2020-02830
SP  - 107 - 115
PY  - 2020
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000506088200016
DO  - DOI:10.1021/acs.cgd.9b00728
UR  - https://juser.fz-juelich.de/record/878394
ER  -