Observation of a Narrow Pseudogap near the Fermi Level of AlCuFe Quasicrystalline Thin Films

Klein, T.; Symko, O. G.; Davydov, D. N.; Jansen, A. G. M.

doi:10.1103/physrevlett.74.3656

Cited by 70 publications

(46 citation statements)

References 26 publications

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“…The surface of the i-Al-Pd-Mn monograin cut perpendicular to a twofold symmetry axis has been sputtered and annealed to 650°C. Its XPS composition is found to be Al 73 Pd 22 Mn 5 . 18 Due to the forward-focusing properties of photoelectrons in the keV regime, the pattern nicely highlights densely packed high-symmetry ͑two-, three-and fivefold͒ axes of the icosahedral point group, as displayed in Fig.…”

Section: -12mentioning

confidence: 99%

“…On the other hand, Wu et al 5 used an expression of the form ϰ(1ϪE/E F ) ␣ connecting to the square-root behavior of a Van Hove singularity. Tunneling spectroscopy 22 and photoemission 23 data have also been fitted using a ͱE contribution in connection with a scaling theory of the metalinsulator transition in amorphous materials. 24 However, we find that a ͱE fit or even one of the form aϩb(E)…”

Section: Rapid Communicationsmentioning

confidence: 99%

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Quasicrystalline nature of quasicrystal surfaces: A photoemission study

et al. 1999

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Section: -12mentioning

confidence: 99%

Section: Rapid Communicationsmentioning

confidence: 99%

Quasicrystalline nature of quasicrystal surfaces: A photoemission study

et al. 1999

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“…1͒ agrees well with the experimental results obtained from tunneling and point contact spectroscopy measurements, where the presence of a dip feature of small width ͑20-60 meV͒, superimposed onto a broad ͑0.5-1 eV͒ asymmetric pseudogap, has been reported. 23,[31][32][33] Thus, Eq. ͑2͒ satisfactorily describes the electronic structure of these alloys in terms of a wide Lorentzian peak ͑related to the Fermi surface-Brillouin zone interaction͒ plus a narrow Lorentzian peak ͑related to sp-d hybridization effects͒.…”

Section: ͑2͒mentioning

confidence: 99%

Optimizing the thermoelectric efficiency of icosahedral quasicrystals and related complex alloys

Maciá

2009

Phys. Rev. B

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In this work we analyze the potential role of quasicrystals and related alloys in thermoelectric material research. Relatively large figure of merit values are expected for those samples exhibiting two properly located narrow features in the density of states close to the Fermi level. It is expected that optimized quasicrystals will perform better at relatively low temperatures, whereas the ZT curve of complex metallic alloys reaches its maximum at high temperatures. Among state-of-the-art quasicrystals most promising samples for thermoelectric applications are found in the AlPd͑Mn,Re͒ system. Quasicrystalline and related approximants in the ScMgCuGa and CaAuIn systems, synthesized on the basis of pseudogap tuning concepts, appear as promising candidates as well.

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“…The overall behavior of this curve agrees well with the experimental results obtained from tunneling and point contact spectroscopy measurements, where the presence of a dip feature of small width (20-60 meV, narrow Lorentzian), superimposed onto a broad (0.5-1 eV, broad Lorentzian), asymmetric pseudogap has been reported. [21][22][23][24][25] The relative importance of each spectral feature in the overall electronic structure is tuned through the weight factor A in Eq. …”

Section: ͑7͒mentioning

confidence: 99%

Compatibility factor of segmented thermoelectric generators based on quasicrystalline alloys

Maciá

2004

Phys. Rev. B

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In this work we present a prospective study on the possible use of certain quasicrystalline alloys in order to improve the efficiency of segmented thermoelectric generators. To this end, we obtain a closed analytical expression for their compatibility factor [G. J. Snyder and T. S. Ursell, Phys. Rev. Lett. 91, 148301 (2003)]. By comparing our analytical results with available experimental data we conclude that a promising high temperature material, compatible with benchmark thermoelectric materials, can be found among AlPdMn based icosahedral quasicrystals. The efficiency of a thermoelectric device depends on the transport properties of the constituent materials and the temperature difference between the hot and cold sides, which sets its Carnot upper limit. Evaluation of new materials for thermoelectric applications is usually made in terms of the dimensionless figure of merit,where T is the temperature, ͑T͒ is the electrical conductivity, ␣͑T͒ is the Seebeck coefficient, e ͑T͒ is the charge carrier contribution to the thermal conductivity, and ph ͑T͒ is the lattice contribution to the thermal conductivity. When considering segmented devices one should also consider the compatibility factor defined by 1since materials with dissimilar s vales cannot be efficiently combined in that case. The thermoelectric compatibility of several materials of current technological interest has been recently reviewed, concluding that a semimetallic material with high p-type thermopower is required for development of segmented generators. 2 In the last few years it has been progressively realized that quasicrystals (QCs) deserve some attention as potential thermoelectric materials (TEMs), since they naturally fulfill the Slack's requirements for a material belonging to the "electronic crystal/phonon glass" class. 3-7 Quite interestingly, relatively high, positive thermopower values ͑+100 − 120 V K −1 ͒ have been reported for representatives of the icosahedral AlPdMn and AlPdRe families in the temperature range 300-600 K. [8][9][10] The main aim of this paper is to show that, by a judicious choice of sample's stoichiometry, 11 suitable candidates for a high temperature material, compatible with PbTe, ͑AgSbTe 2 ͒ 0.15 ͑GeTe͒ 0.85 (TAGS) or skutterudites, may be found among the AlPd͑Re, Mn͒ quasicrystalline alloys.To this end, let us start by briefly summarizing some relevant experimental data. In Tables I and II we list the figure of merit and compatibility factors of different QCs as reported in the literature. At room temperature we observe that the largest s values are comparable to those observed in usual TEMs, like Bi 2 Te 3 or SiGe ͑s Ӎ 1 V −1 ͒. 2 At higher temperatures the most promising QC is i-AlPdMn, which exhibits an s factor larger than those reported for SiGe ͑s Ӎ 1 V −1 ͒ and PbTe ͑s Ӎ 1.2 V −1 ͒, and approaches that of TAGS ͑s Ӎ 2.7 V −1 ͒ at T = 550 K. 2 On the other hand, the s factor corresponding to AlPdRe samples is larger at room temperature (where it exhibits a lower ZT value) than it is at higher temperatures...

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Observation of a Narrow Pseudogap near the Fermi Level of AlCuFe Quasicrystalline Thin Films

Cited by 70 publications

References 26 publications

Quasicrystalline nature of quasicrystal surfaces: A photoemission study

Quasicrystalline nature of quasicrystal surfaces: A photoemission study

Optimizing the thermoelectric efficiency of icosahedral quasicrystals and related complex alloys

Compatibility factor of segmented thermoelectric generators based on quasicrystalline alloys

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