Heat-induced spinodal decomposition of Ag–Cu nanoparticles

0449518 - ÚFM 2016 RIV GB eng J - Journal Article
Sopoušek, J. - Zobač, O. - Buršík, Jiří - Roupcová, Pavla - Vykoukal, V. - Brož, P. - Pinkas, J. - Vřešťál, J.
Heat-induced spinodal decomposition of Ag–Cu nanoparticles.
Physical Chemistry Chemical Physics. Roč. 17, č. 42 (2015), s. 28277-28285. ISSN 1463-9076. E-ISSN 1463-9084
Institutional support: RVO:68081723
Keywords : nanoparticle synthesis * CALPHAD * XRD
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 4.449, year: 2015

Solvothermal synthesis was used for Ag–Cu nanoparticle (NP) preparation from metallo-organic precursors. The detailed NP characterization was performed to obtain information about nanoparticle microstructure and both phase and chemical compositions. The resulting nanoparticles exhibited chemical composition inside a FCC_Ag + FCC_Cu two-phase region. The microstructure study was performed by various methods of electron microscopy including high-resolution transmission electron microscopy (HRTEM) at an atomic scale. The HRTEM and X-ray diffraction studies showed that the prepared nanoparticles form the face centred cubic (FCC) crystal lattice where the silver atoms are randomly mixed with copper. The CALPHAD approach was used for predicting the phase diagram of the Ag–Cu system in both macro- and nano-scales. The predicted spinodal decomposition of the metastable Ag–Cu nanoparticles was experimentally induced by heating on an X-ray powder diffractometer (HT XRD). The nucleation of the Cu-rich phase was detected and its growth was studied. Changes in the Ag-rich phase were observed in situ by X-ray diffraction under vacuum. The heat treatment was conducted at different maximum temperatures up to 450 °C and the resulting particle product was analysed. The experiments were complemented by differential scanning calorimetry (DSC) measurements up to liquidus temperature. The start temperatures of the spinodal phase transformation and particle aggregation were evaluated.
Permanent Link: http://hdl.handle.net/11104/0251078