Using molecular dynamics simulations in conjunction with the quantum-corrected Sutton–Chen potential, we studied the influence of the heating and cooling rates, number of particles, temperature and relaxation time on the microscopic structure, phase transitions and dynamics of crystallization in four model systems containing N = 4000, 5324, 6912 and 8788 nickel atoms. The simulation results of a representative ensemble of 5324 Ni atoms have shown that the glass transition temperature, T_g, crystallization temperature, T_c, and melting temperature, T_m, are observed with heating and cooling rates in the range of ΔT/Δt = 2 × 10¹² K s⁻¹ to 4 × 10¹³ K s⁻¹, but T_g or T_c increases while T_m decreases with decreasing ΔT/Δt. By applying ΔT/Δt = 4 × 10¹² K s⁻¹ we found that after cooling from 2000 K down to 300 K the Ni atoms form nanoparticles for which the grain size follows the relation d ∝ N^−1/3, and simultaneously the total potential energy of the investigated systems decreases linearly with the number of Ni atoms. With the help of common neighbor analysis, we detected the coexistence of amorphous and crystalline phases during the whole crystallization process. In the solid state, the dominant crystalline phase is characterized by the FCC and HCP structures, although a very small fraction of the BCC structure may occur at 300 K. It was established that the formation of the FCC structure is favored over the HCP one. In particular, lowering the temperature and increasing the relaxation time favour crystallization of the FCC lattice.

Herein, we carefully investigated the Fe³⁺ doping effects on the structure and electron distribution of Cr₂O₃ nanoparticles using X-ray diffraction analysis (XRD), maximum entropy method (MEM), and density functional theory (DFT) calculations. We showed that increasing the Fe doping induces an enlargement in the axial ratio of c/a, which is associated with an anisotropic expansion of the unit cell. We found that as Fe³⁺ replaces Cr in the Cr₂O₃ lattice, it caused a higher interaction between the metal 3d states and the oxygen 2p states, which led to a slight increase in the Cr/Fe–O1 bond length followed by an opposite effect for the Cr/Fe–O2 bonds. Our results also suggest that the excitations characterize a well-localized bandgap region from occupied Cr d to unoccupied Fe d states. The Cr₂O₃ and Fe-doped Cr₂O₃ nanoparticles behave as Mott–Hubbard insulators due to their band gap being in the d−d gap, and Cr 3d orbitals dominate the conduction band. These findings suggest that the magnitude and the character of the electronic density near the O atom bonds in Cr₂O₃ nanoparticles are modulated by the Cr–Cr distances until its stabilization at the induced quasi-equilibrium of the Cr₂O₃ lattice when the Fe³⁺ doping values reaches the saturation level range.

In our paper, we study the effects of pseudopotential and concentration of Au doping (0, 25, 50, 75, 100%) on the geometric structure and electronic structures of AgAu alloys. For this purpose, we use ab initio quantum calculations in the Material Studios software. The geometric structures of materials are confirmed through the lattice constant, crystal structure, and total energy of the unit cells (E_tot). Electronic structures of the materials are confirmed by band gap (E_g), projected density of states (PDOS), and total density of states (DOS). The obtained results show that the pseudopotential and concentration of Au doping on AgAu alloys play an important role in the origin of the physical properties of AgAu alloys.

In this study, to explore the effect of Co contents on the electroplated Fe–Co–Ni samples, three different Fe–Co₃₃–Ni₆₂, Fe–Co₄₃–Ni₅₃, and Fe–Co₆₁–Ni₃₆ samples were electrochemically grown from Plating Solutions (PSs) containing different amounts of Co ions on indium tin oxide substrates. Compositional analysis showed that an increase in the Co ion concentration in the PS gives rise to an increment in the weight fraction of Co in the sample. In all samples, the co–deposition characteristic was described as anomalous. The samples exhibited a predominant reflection from the (111) plane of the face–centered cubic structure. However, the Fe–Co₆₁–Ni₃₆ sample also had a weak reflection from the (100) plane of the hexagonal close–packed structure of Co. An enhancement in the Co contents caused a strong decrement in the crystallinity, resulting in a decrease in the size of the crystallites. The Fe–Co₃₃–Ni₆₂ sample exhibited a more compact surface structure comprising only cauliflower–like agglomerates, while the Fe–Co₄₃–Ni₅₃ and Fe–Co_61–Ni₃₆ samples had a surface structure consisting of both pyramidal particles and cauliflower–like agglomerates. The results also revealed that different Co contents play an important role in the surface roughness parameters. From the magnetic analysis of the samples, it was understood that the Fe–Co₆₁–Ni₃₆ sample has a higher coercive field and magnetic squareness ratio than the Fe–Co₄₃–Ni₅₃ and Fe–Co₃₃–Ni₆₂ samples. The differences observed in the magnetic characteristics of the samples were attributed to the changes revealed in their phase structure and surface roughness parameters. The obtained results are the basis for the fabrication of future magnetic devices.