Characteristic atom sequences of Nb-Mo alloys system in BCC structure and properties of disordered alloys

Comprehensively considering energy, volume and electronic structure of alloys, the ninth equation was determined as the interaction function of Nb-Mo alloys system in BCC structure on the basis of idea of systematic science of alloys, experimental lattice constants and heats of formation of disordered Nb（1-x）Mox alloys. The structural parameters and properties of Nb and Mo characteristic atoms sequences and corresponding characteristic crystals sequences were determined in Nb-Mo alloys system. The electronic structure and physical properties of disordered Nb（1-x）Mox alloys system were calculated according to concentration of characteristic atoms of disordered alloys. The change trend of physical properties is the same as that of electronic structure.

Thickness dependence of the anomalous Hall effect in disordered face-centered cubic FePt alloy films

The anomalous Hall effect in disordered face-centered cubic(fcc) FePt alloy films is experimentally studied. The longitudinal resistivity independent term of the anomalous Hall conductivity(AHC) increases and approaches saturation with increasing film thickness. The contribution of side jump scattering is suggested to decrease monotonically with increasing film thickness, which can be ascribed to the variation of the surface scattering with the film thickness. The sign of the skew scattering contribution to the AHC is opposite to that of the intrinsic contribution in the system.

Time-resolved Photoluminescence Spectra of Nominally Disordered GaInP Alloy

Luminescence decay and time resolved photoluminescence(TRPL) spectra are used for study on the transient luminescence process of the nominally disordered GaInP alloy. The luminescence decay of GaInP alloy shows the temperature and excitation intensity dependent characters. At 77 K and under high excitation intensity, the luminescence decay shows single exponential time dependence, while under low excitation intensity or at 300 K, the luminescence decay shows double exponential time dependence. The analysis indicates that this nominally disordered GaInP alloy actually exhibits a very weak degree of order. The blue shift of PL peak is observed in the TRPL spectra at 77 K, which is derived from the transfer of the carriers from the ordered domain to the disordered region of the alloy. At 300 K, due to the thermal quenching, the transfer is too weak to be observed. However, The recombination of the carriers between the ordered domain and the disordered region is still devoted to luminesce.

First principles study on the electronic structure and magnetism of Fe1-xCoxSi alloys

Electronic and magnetic properties of Fe1-xCoxSi alloys were investigated by using a full-potential linear augmented-plane-wave method based on density functional theory. Electronic structure calculation demonstrates that half-metallic property appears in the Fe-rich region of 0 〈 x ≤ 0.25, while the alloys turn out to be a magnetic metal for x 〉 0.25. The concentration dependence of the magnetic moment of the alloys can be understood by the fixed Fermi level at minority band in Fe-rich region, as well as at the majority band in Co-rich region. In Fe-rich alloys, the electronic structure and the magnetic properties at Fe site depend mainly on the spin-polarization of nearest neighbouring Co atoms, while in Co-rich alloys, these features at Co site arise mainly from the neighbours of Fe atoms.

Research on properties of DO_3- and B2-type ordered alloys and disordered alloys in Nb-Mo alloy system in BCC structure

Based on the idea of systematic science of alloys, we derived the interaction equations of binary alloys in BCC structure in this paper. According to the basic information of characteristic atoms sequences and characteristic crystals sequences of Nb-Mo alloy system and the concentrations of characteristic atoms of Nb-Mo alloy system, the properties of DO3-Nb3Mo type ordered alloys, B2-NbMo type ordered alloys and DO3-NbMo3 type ordered alloys and disordered alloys were calcu-lated. The results show that the properties of ordered alloys exhibit stronger variations than those of disordered Nb(1-x)Mox alloys when approaching the stoichiometric ratio, whereas the opposite trend occurs when deviating from the stoichiometric ratio. The main reason is that the ordering degree is maximal at the stoichiometric ratio while it decreases linearly when deviating from stoichiometric ratio. On the contrary, the number of bonding electrons among atoms increases with the simultaneous decreasing of the nearly free electrons, which shortens the bond lengths and thus strengthens the crystal bonding.