In this manuscript we show a new concept of structural determination of complex metallic alloys by nuclear magnetic resonance (NMR). By measuring angular dependence of the NMR spectra of monocrystals we were able to extract the local symmetry around the nucleus. This helped us to confirm the existence of deformed icosahedral clusters found in ksi’-AlPdMn and configurational disorder present in beta-Al3Mg2 samples. We showed for the first time good agreement between calculated and experimentally determined electric field gradients in complex metallic alloys.
COBISS.SI-ID: 20494375
In this manuscript we describe magnetic, electric and thermal properties of beta-Al3Mg2 complex metallic alloy with 1168 atoms in the unit cell. We propose theoretical models to reproduce experimental observation, which give acceptable agreement despite structural complexity. Electric resistivity shows almost temperature-independent behavior in a wide range from 4 K to 300 K, similar to results obtained in ksi’-AlPdMn.
COBISS.SI-ID: 20939815
We present a detailed study of the anisotropic transport properties of a single-crystalline Al80Cr15Fe5 complex metallic alloy. Temperature dependent electrical resistivity along the b and c crystalline directions shows a nonmetallic behavior, whereas it shows a metallic positive temperature coefficient along the a direction. Structural considerations of the Al80Cr15Fe5 phase show that the anisotropy of the transport properties is a consequence of anisotropic atomic order on the scale of nearest-neighbor atoms, suggesting that the role of quasiperiodicity in decagonal quasicrystals is marginal
COBISS.SI-ID: 21249831
We have investigated anisotropic physical properties of Y-Al-Ni-Co decagonal approximant The crystalline-direction-dependent measurements were performed along three orthogonal directions a*, b and c of the Y-Al-Ni-Co unit cell, where (a,c) monoclinic atomic planes are stacked along the perpendicular b direction. These anisotropies are analyzed in terms of the anisotropic structure of the Y-Al-Ni-Co phase and the ab initio calculated anisotropic Fermi surface. The results are compared with the literature reported anisotropy of the physical properties of the d-Al-Ni-Co decagonal quasicrystal.
COBISS.SI-ID: 21987879
Single crystals of boron-doped Ba8Al14Si31 clathrate were prepared using Al flux growth. The structure and elemental composition of the samples were characterized by single-crystal and powder X-ray diffraction; and multinuclear 27Al, 11B, and 29Si nuclear magnetic resonance (NMR). Solid-state NMR provides further evidence for boron doped into the framework structure. Temperature dependent resistivity indicates metallic behavior, whereas thermal conductivity is low.
COBISS.SI-ID: 21947687