Exponential surface melting of Cu nanoparticles observed by in-situ TEM

Simulations of the Oxidation and Degradation of Platinum Electrocatalysts

“…The rearranged system is expected to be a more realistic representation of the catalyst's structure than the pristine (perfect) system considering the stresses acting on the particle due to repeated reductive jumps and the thermal discharge generated by the ORR on the particle surface. The latter can cause local surface melting which was recently observed for Cu NPs to occur significantly below the actual melting temperature . To lend more significance to the rearranged model, in the following text, all values are averaged over 5 different particles, generated from initially oxidized structures with x O = 0.1–0.5.…”

Nano-crystal melting calculation for Al, Cu and Ag considering macro-crystal surface melting

“…Taking into consideration eqn (27), the corresponding nanophase diagram of Al, Cu and Ag is calculated respectively superimposed with the reasonable literature data, 54,56,[59][60][61][62][63]67,68,74,[76][77][78]80,81,83,86,89,[91][92][93] as illustrated in Fig. 5.…”

“…Then Manai and Delogu 68 reported that the heterogeneous melting points of Cu for 4 and 8 nm particles were 1180 and 1220 K, respectively. The melting temperature of Cu nanoparticles with a diameter of B30 nm was observed by Wang et al 74 using in situ heating high-resolution transmission electron microscopy (HRTEM). With respect to Ag nanoparticles, Zhao et al 76,77 combined MD simulations and the surface premelting model to study the melting properties.…”

“…The size-dependent melting temperature of Al, Cu and Ag has been studied by several groups. 51–93 The melting behavior of nanocrystalline Al was experimentally investigated using differential scanning calorimetry (DSC) by Eckert et al 54 Later, the melting points of Al at different nanoparticle radii were ascertained by Alavi and Thompson 56 using MD simulations. This method was also performed by Puri and Yang 59 to predict the melting of nanosized Al particles in the range of 2–9 nm.…”

Characterization of a Nanocrystalline Structure Formed by Crystal Lattice Transformation in a Bulk Steel Material

“…The use of both physical and chemical methods, such as gas-phase condensation [4] and electrodeposition [5,6], for the synthesis of such nanomaterials, have been reported in abundance. Nanomaterials include quantum dots and small nanoparticles (zero-dimensional) [7,8], nanotubes and nanowires (one-dimensional) [9,10], nanofilms and nanocoatings (two-dimensional) [11,12], and more complex structures (three-dimensional) [13]. However, bulk materials are still the dominant materials used for engineering applications.…”