Au–Pd–Zr ternary alloy phase diagram at 25 °C was calculated by Panda phase calculation software, and the thermodynamic data were based on three binary alloy phase diagrams: Pd–Au, Au–Zr, and Pd–Zr. Five composition points in the ternary phase diagram were selected to predict the precipitation order. One (32Au–32Pd–36Zr) of the five composition points in ternary phase diagram was chosen to verify the correctness of the phase diagram calculation and the precipitation order by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The unknown phase in XRD patterns was predicated by EDS and materials studio (MS) software. The experimental results show that there are seven key ternary reactions points and 17 phase regions in all isothermal sections at 25 °C. The thermodynamic process and microstructure for the alloy phase can be described in order according to the vertical section in phase diagram. The phase compositions of the chosen one point are consistent with calculation prediction. The unknown phase in XRD patterns should be Zr2AuPd by the first principle X-ray simulation.

The stability, thermal and mechanical properties of PtxAly intermetallic compounds are investigated by density functional theory (DFT). The cohesive energy and formation enthalpy of PtxAly phases show that they are thermodynamically stable structures and these are in good agreement with the experiments. The heat capacity of the compounds is calculated by quasi-harmonic approximation (QHA) method. The thermal expansion coefficient as a function of temperature for each compound is also discussed. The elastic properties such as bulk modulus, Young’s modulus are evaluated by Viogt–Reuss–Hill approximation. The anisotropic properties of sound velocities for the PtxAly compounds are explored. The calculated Poisson’s ratio varies from 0.26 to 0.39 for PtxAly phases and the bonds in the compounds are mainly metallic and covalent types.Highlights► The calculated stabilities of PtxAly compounds in Al–Pt system are consist with the experiments. ► The elastic properties of PtxAly compounds have been reported which will help scientist to design advanced materials in high temperature. ► The anisotropic sound velocities, heat capacities, thermal expansion coefficients of PtxAly binary compounds have been reported.

The mechanical properties of nano-scale Cu/FeS composite were simulated by molecular dynamics (MD) simulation in this paper. Through the analysis on the stress-strain curves, the results of MD simulation were in good agreement with mechanisms of macroscopic deformation. When the size of particles was smaller than a certain value, the relationship between yield strength and size, which was different from the large size crystals abided by the contrary Hall-Petch relationship. Based on the discussion of nano-scale Cu/FeS composite, some interesting conclusions were obtained. For example, the “S” type curves were discovered in stress-strain curves and the anisotropy of FeS was very evident when the exposures of reinforcing phase (FeS) were different and so on. The basic theories and calculations of the composite that contains nano-scale particles were discussed. At the same time, a new modeling building method of composites, which was close to actual experiences, were considered in this paper.

Bulk crystal properties of Ag2SnO3 were investigated with the advantage of density functional theory. The whole structure has layered feature: hexagonal metallic planes formed by Ag atoms and distorted octahedrons of SnO6 clusters are configured alternatively along c axis of hexagonal cell. The cohesive energy is about −2.792 eV/atom, which is less than SnO2. The Debye temperature of Ag2SnO3 is about 231.6 K, and the bulk and shear moduli are 62.13 and 20.63 GPa, respectively. Band structure and DOS show the compound has a small pseudo-band gap value of 1.0 eV and so may be a semiconductor. When checking the PDOS intensity at the Fermi surface of Ag atoms, a weak metallic character can be seen. The distortion mechanism becomes less effective to reduce the total orbital energy both in SnO2 and in Ag2SnO3 and as a result the bond lengths of Sn–O are intended to be isotropy. The structure of Ag2SnO3 studied here has a hexagonal primitive cell with the space group of P6322, Ag atom which located in SnO6 layer, almost coplanar with Sn atoms has a large coordination numbers as 12, including 6 Sn–O bonds and 6 Sn–Ag bonds. Interestingly, the whole structure has layered feature, hexagonal metallic planes formed by Ag atoms and distorted octahedrons of SnO6 clusters are configured alternatively along c axis of hexagonal cell. These characters are similar to magnetoresistive manganites and superconducting cuprates, may be a new structure of superconductivity structure or charge ordering phenomenon for functional materials.

AgCuO2 and Ag2Cu2O3 are new types of semiconductor materials. A theoretical study is presented for both the electronic and optical properties of these new photovoltaic materials in the framework of density functional theory (DFT). The calculated cohesive energy is −3.606 eV/atom and −3.723 eV/atom for Ag2Cu2O3 and AgCuO2, respectively. Electronic calculations indicate that AgCuO2 is a small band gap semiconductor and Ag2Cu2O3 is metallic in nature. The valency state of Cu is divalent in Ag2Cu2O3 and trivalent in AgCuO2. The largest absorption coefficient of CuO2 is 332 244, which is significantly greater than that of CuInSe2, CdTe, GaAs, etc.

AgCuO2 and Ag2Cu2O3 are new types of semiconductor materials. A theoretical study is presented for both the electronic and optical properties of these new photovoltaic materials in the framework of density functional theory (DFT). The calculated cohesive energy is −3.606 eV/atom and −3.723 eV/atom for Ag2Cu2O3 and AgCuO2, respectively. Electronic calculations indicate that AgCuO2 is a small band gap semiconductor and Ag2Cu2O3 is metallic in nature. The valency state of Cu is divalent in Ag2Cu2O3 and trivalent in AgCuO2. The largest absorption coefficient of CuO2 is 332 244, which is significantly greater than that of CuInSe2, CdTe, GaAs, etc.