Universality of the Hall-effect anisotropy in decagonal quasicrystals

Wang, Yunping; Dian-lin, Zhang; Chen, L. F.

doi:10.1103/physrevb.48.10542

Cited by 27 publications

(8 citation statements)

References 25 publications

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“…[1] produced an importante research on these phases in the system Al Cu Co (Si). Moreover, QC phases obtained in this system were also reported with special electrical properties [2][3][4]. It is important to not , that these QC systems show a strong variation of the conductivity with a very slighhht change in composition.…”

mentioning

confidence: 52%

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.

2003

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The discovery of a stable decagonal QC phase in Al Cu Co by He et. al. [1] produced an importante research on these phases in the system Al Cu Co (Si). Moreover, QC phases obtained in this system were also reported with special electrical properties [2-4]. It is important to not , that these QC systems show a strong variation of the conductivity with a very slighhht change in composition. In agreement with differents authors, the electrical conductivity of the decagonal quasi-crystalls of the Al Cu Co (Si) alloy shows metallic behavior along to periodic direction and nonmetallic behavior along to quasiperiodic direction. In this work we show some HRTEM results that indicate a different behavior of the electrical conductivity for decagonal phase af the Al 62 Cu 20 Co 15 Si 3 alloy that was produced using a double elliptic mirror furnace with slow thermal inertial.We confirmed the decagonal structure of the Al Cu Co Si grains by a tilting series of salected area diffraction patterns, Fig. 1. We obtained, that the quality of their atomic resolution electron microscope images is modify drastically with the composition of the alloy. Therfore, we find that the HRTEM images from our alloy were almost impossible to obtain because the lack of electrical conductivity of the sample produced too much astigmatism. The best images obtained are present in figure 2. Campare these with those obtained by Reyes-Gasga et al. [5] in a sample with different composition. In that case, this kind of aberration was not present. The sample was ground and supported in cooper grids for the their trasmision electron microscope analysis. Electron difraction patterns, tilting experiments were obtained using a JEOL 100CX analytical electron microscope equipped with ± 60 0 goniometer. Chemical analysis were carried out using a JEOL 2010F analytical electron microscope equipped with a ± 22 0 goniometer and a NORAN energy-dispersive X-ray analyzer For high resolution observation a JEOL 4000EX high resolution electron microcope was used.

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mentioning

confidence: 52%

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.

2003

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“…Here it is worth mentioning that the anisotropic Hall coefficient of the d-Al-Ni-Co-type QCs shows similar duality, being also holelike R H Ͼ 0 for the field lying in the quasiperiodic plane and electronlike R H Ͻ 0 for the field along the periodic direction. 5,6 This duality is proposed to be a universal feature of d-QCs.…”

Section: Hall Coefficientmentioning

confidence: 97%

“…This R H anisotropy was reported for the d-Al-Ni-Co, d-Al-Cu-Co, and d-Al-Si-Cu-Co and is considered to be a universal feature of d-QCs. 5,6 The degree of anisotropy of the transport coefficients is related to the structural details of a particular decagonal phase, depending on the number of quasiperiodic layers in one periodic unit. 10,11 The most anisotropic case are the phases with just two layers, realized in d-Al-Ni-Co and d-Al-Cu-Co, where the periodicity length along the periodic axis is about 0.4 nm and the resistivity ratio at RT amounts typically Q / P Ϸ 6 -10.…”

Section: Introductionmentioning

confidence: 99%

Anisotropic magnetic and transport properties of orthorhombicAl13Co4

et al. 2009

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We have investigated anisotropic physical properties ͑magnetic susceptibility, electrical resistivity, thermoelectric power, Hall coefficient, and thermal conductivity͒ of the o-Al 13 Co 4 , an orthorhombic approximant to the decagonal phase. The crystallographic-direction-dependent measurements were performed along the a, b, and c directions of the orthorhombic unit cell, where ͑b , c͒ atomic planes are stacked along the perpendicular a direction. Magnetic susceptibility is predominantly determined by the Pauli-spin paramagnetism of conduction electrons. The in-plane magnetism is stronger than that along the stacking a direction. Anisotropic electrical and thermal conductivities are the highest along the stacking a direction. The anisotropic thermoelectric power changes sign with the crystallographic direction and so does the anisotropic Hall coefficient which changes from negative electronlike to positive holelike for different combinations of the electric current and magnetic-field directions. The investigated anisotropic electrical and thermal transport coefficients were reproduced theoretically by ab initio calculation using Boltzmann transport theory and the calculated anisotropic Fermi surface. The calculations were performed for two structural models of the o-Al 13 Co 4 phase, where the more recent model gave better agreement, though still qualitative only, to the experiments.

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“…The in-plane isotropy of S Q suggests that the Fermi surface of d-Al-Co-Ni is a rotational body around the 10-fold symmetry axis. The rotational symmetry of the Fermi surface was also proposed to be at the origin of the negative electron-type value of R 10 H for the field application along the 10-fold axis, as elaborated by Yun-ping et al, 24 whereas the positive hole-type R Q H for the in-plane field application was proposed to reflect the Fermi surface curvature typical of nearly full bands in the cross sections perpendicular to the 10-fold symmetry direction. The anisotropies and the temperature dependences of the S 10 , S Q , R 10 H , and R Q H parameters are sensitive to the details of the d-Al-Co-Ni-specific Fermi surface and can be affected by the anisotropic phonon spectrum.…”

Section: Thermopower and Hall Coefficientmentioning

confidence: 98%

Intrinsic anisotropic magnetic, electrical, and thermal transport properties ofd-Al-Co-Ni decagonal quasicrystals

et al. 2012

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To address the questions on the anisotropy of bulk physical properties of decagonal quasicrystals and the intrinsic physical properties of the d-Al-Co-Ni phase, we investigated the anisotropic magnetic susceptibility, the electrical resistivity, the thermoelectric power, the Hall coefficient, and the thermal conductivity of a d-Al-Co-Ni single crystal of exceptional structural quality. Superior structural order on the local scale of atomic clusters was confirmed by 27 Al nuclear magnetic resonance spectroscopy. The measurements were performed in the 10-fold periodic direction of the structure and in three specific crystallographic directions within the quasiperiodic plane, corresponding to the 2 and 2 twofold symmetry directions and their bisector. The specific heat, being a scalar quantity, was determined as well. The measurements of the second-rank bulk tensorial properties confirm the theoretical prediction that a solid of decagonal point group symmetry should exhibit isotropic physical properties within the quasiperiodic plane and anisotropy between the in-plane and the 10-fold directions. d-Al-Co-Ni is an anisotropic diamagnet with stronger diamagnetism for the magnetic field in the 10-fold direction. Electrical and thermal transport is strongly metallic in the 10-fold direction but largely suppressed within the quasiperiodic plane, the main reason being the lack of translational periodicity that hinders the propagation of electrons and phonons in a nonperiodic lattice. The third-rank Hall-coefficient tensor shows sign-reversal anisotropy related to the direction of the magnetic field when applied in the 10-fold direction or within the quasiperiodic plane. The observed anisotropy is not a peculiarity of quasicrystals but should be a general feature of solids with broken translational periodicity in two dimensions.

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Universality of the Hall-effect anisotropy in decagonal quasicrystals

Cited by 27 publications

References 25 publications

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.

Anisotropic magnetic and transport properties of orthorhombicAl13Co4

Intrinsic anisotropic magnetic, electrical, and thermal transport properties ofd-Al-Co-Ni decagonal quasicrystals

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Universality of the Hall-effect anisotropy in decagonal quasicrystals

Cited by 27 publications

References 25 publications

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al62 Cu20 Co15 Si3 alloy.

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al62 Cu20 Co15 Si3 alloy.

Anisotropic magnetic and transport properties of orthorhombicAl13Co4

Intrinsic anisotropic magnetic, electrical, and thermal transport properties ofd-Al-Co-Ni decagonal quasicrystals

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Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.

Evidence by HRTEM of lower conductivity along the periodic direction than along the quasiperiodic directionof of the decagonal quasi-crystalline phase of the Al₆₂ Cu₂₀ Co₁₅ Si₃ alloy.