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In this paper, we have successfully grown the high-quality ScNiBi single crystals by a Bi flux method and investigated their electronic-transport properties. It was found that the ScNiBi single crystal is a gapless semiconductor with positive linear magnetoresistance (MR). Moreover, the field-dependent MR in the low-field region has demonstrated obvious weak antilocalization (WAL) effect below 50 K. The extremely large prefactor α and angle-dependent magnetoconductance ΔGxx suggest that the WAL effect originates from the contribution of a strong bulk spin-orbital coupling. [ABSTRACT FROM AUTHOR]

Solid state 93Nb nuclear magnetic resonance spectroscopy has been employed to investigate the atomic and electronic structures in Ni-Nb based metallic glass (MG) model system. 93Nb nuclear magnetic resonance (NMR) isotropic metallic shift of Ni60Nb35Sn5 has been found to be ∼100 ppm lower than that of Ni60Nb35Zr5 MG, which is correlated with their intrinsic fracture toughness. The evolution of 93Nb NMR isotropic metallic shifts upon alloying is clearly an electronic origin, as revealed by both local hyperfine fields analysis and first-principle computations. This preliminary result indicates that, in addition to geometrical considerations, atomic form factors should be taken into a description of atomic structures for better understanding the mechanical behaviors of MGs. [ABSTRACT FROM AUTHOR]

It is generally believed that there is no simple relationship between ultimate fracture strength and stiffness for an elastically isotropic material. By taking bulk metallic glasses (BMGs) as model materials, the relation between ultimate fracture strength and elastic moduli was analyzed within Griffith theory framework. The observed correlation between elastic moduli and fracture strength in BMGs reveals the effects of BMG defects and plastic zone size on the crack resistance of these model materials. [ABSTRACT FROM AUTHOR]

We report the observation of nanoscale striped periodic pattern with similar distinctive characteristics independent of loading conditions on the fracture surface of various bulk metallic glasses. We demonstrate that the periodic stripes are formed by the orderly assembly of nanoscale regular dimples. The similarities between our observed striped pattern and various unequilibrium systems such as oscillating granular and colloidal suspensions systems are found. By drawing an analogy between glassy and granular materials, we propose a model that can capture and simulate the characteristics of the observed corrugations. Our results would provide insight into the origin of fracture surface roughening in brittle materials. [ABSTRACT FROM AUTHOR]

We investigate the electronic structures, magnetic properties and half-metallicity of Heusler compounds Hf2VZ (Z = Ga, In, Tl, Si, Ge, Sn and Pb) with Hg2CuTi-type structure by using the first-principle calculations based on density-functional theory. It is found that the equilibrium lattice constants of Hf2VZ (Z = Ga, In, Tl, Si, Ge, Sn and Pb) compounds are 6.68, 6.88, 6.91, 6.57, 6.63, 6.85 and 6.94 Å, respectively. Hf2VZ (Z = Ga, In, Tl, Si and Sn) compounds exhibit half-metallicity at their respective equilibrium lattice constants. Hf2VGe and Hf2VPb do not exhibit half-metallicity at their equilibrium lattice constants but can present the half-metallicity when the lattice constant decreases to 6.51 and 6.71 Å, respectively. In case of the lattice thermal expansion, the half-metallicity can be kept in the range of 6.30∼ 7.27, 6.36∼ 7.80, 6.46∼ 7.35, 6.00∼ 6.70 and 6.10∼ 6.95 Å (lattice constant) for Hf2VZ (Z = Ga, In, Tl, Si and Sn). Under the unaxial strain, the half-metallicity can still be kept for Hf2VZ (Z = Ga, In, Tl) when the lattice distortion is up to ± 10% (c/a) and be kept for Hf2VZ (Z = Si, Sn) when the lattice distortion is 0.88∼ 1.09, 0.91∼ 1.09 (c/a). For the Hf2VZ compounds with half-metallicity, the total magnetic moment is 2 μB when Z is the third main group elements and is 1 μB when Z is the fourth main group elements. The Hf2VZ compounds with half-metallicity obey the Slater-Pauling formula: Mt = 18 − Zt rule. [ABSTRACT FROM AUTHOR]

The atomic and electronic structures of LnAl(2) (Ln=Y, La and Lu) on Al sites were characterized by (27)Al solid state NMR spectroscopy. (27)Al isotropic metallic shifts have been determined in these cubic laves phases under both static and magic angle spinning (MAS) conditions. Based on band structure calculations, we found a strong correlation of (27)Al isotropic metallic shifts and s character of the density of states at the Fermi level on Al sites. We also found tetrahedral distortion of Al centered clusters, which can be well characterized by quadruple coupling constants and Knight shift anisotropy., (Copyright © 2011 Elsevier Inc. All rights reserved.)