We synthesized Ag@Ni core-shell nanoparticles by the solvothermal hot injection method and characterized them as for their shape and size by dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM). We previously demonstrated their core-shell structure by scanning transmission electron microscopy with energy dispersive spectroscopy (STEM-EDS). The silver/nickel phase diagram was calculated by the CALPHAD method, and the melting points of 10, 15, and 20 nm silver nanoparticles were predicted at 930.2, 940.7, and 946.0 °C, respectively. We took advantage of the nickel shell to avoid silver sintering and to confirm the calculated melting point depression (MPD). The results obtained from the differential scanning calorimetry (DSC) experiments revealed the melting points of 11–15 nm nanoparticles at 944–949 °C in agreement with calculated values.

The results of this research have been acquired within the Czech Science Foundation project GA 17-15405S, the H2020 Twinning project SINNCE (No. 810626), and the CEITEC 2020 (LQ1601) project with the financial contribution made by the MEYS CR within special support paid from the National Program for Sustainability II funds. Also, the CIISB research infrastructure project LM2015043 funded by MEYS CR is gratefully acknowledged for the financial support of the measurements at the CF X-ray Diffraction and Bio-SAXS. Access to computing and storage facilities owned by parties and project contributing to the National Grid Infrastructure MetaCentrum provided under the programme "Projects of Large Research Development, and Innovations Infrastructures" (CESNET LM2015042), is highly appreciated. The authors thank Dr. K. Novotny and L. Simonikova for ICP-OES analyses.