NMR probe of pseudogap characteristics in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi mathvariant="normal">Ca</mml:mi><mml:msub><mml:mi mathvariant="normal">Al</mml:mi><mml:mrow><mml:mn>2</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">Si</mml:mi><mml:mrow><mml:mn>2</mml:mn><mml:mo>+</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>

Lue, Chin‐Shan; Wang, S. Y.; Fang, Chi

doi:10.1103/physrevb.75.235111

Cited by 9 publications

(11 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From the determined 1/T 1K T values, we can obtain g R s (E F ) = 0.0037 states/eV atom for SrAl 2 Si 2 , and fewer than 0.0068 states/eV atom measured in this way for CaAl 2 Si 2 . 11 We also extracted g R s (E F ) values for other compositions, showing a gradual increase with increasing x in Sr 1−x Y x Al 2 Si 2 , which is consistent with the Knight shift analysis.…”

supporting

confidence: 71%

“…For the present Sr 1−x Y x Al 2 Si 2 , the quadrupole frequency ν Q was determined directly from these lines. The obtained ν Q = 0.31 ± 0.01 MHz remains nearly unchanged with different doping levels x and this value is slightly smaller than that of CaAl 2 Si 2 (ν Q = 0.36 ± 0.02 MHz), 11 indicating weaker quadrupole interactions in Sr 1−x Y x Al 2 Si 2 .…”

mentioning

confidence: 39%

“…8 CaAl 2 Si 2 , isostructural to SrAl 2 Si 2 , and some silicides such as SrSi 2 , also feature Fermi-level pseudogaps which were found to govern the electronic properties of the materials. [9][10][11][12][13][14] In general, the pseudogap characteristics are very sensitive to external effects such as chemical substitution. Hence, altering the composition allows a change of the electronic properties, and thus provides valuable information about the influence of the local environment on the structural and electronic behavior of gapped materials.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Evolution of the pseudogap in Sr1−xYxAl

2011

Self Cite

View full text Add to dashboard Cite

With the aim of providing microscopic information about the electronic characteristics of SrAl 2 Si 2 and effects of chemical substitution on its pseudogap features, we carried out a study on Sr 1−x Y x Al 2 Si 2 (x = 0, 0.05, 0.1, and 0.15) by means of 27 Al nuclear magnetic resonance (NMR) spectroscopy. For stoichiometric SrAl 2 Si 2 , the temperature-dependent NMR Knight shift and spin-lattice relaxation rate are associated with a sharp feature in the electronic density of state within a pseudogap at around the Fermi level. On the other hand, the NMR observations for Y-substituted compounds exhibit ordinary metallic behavior, suggesting that the Fermi level has moved out of the pseudogap for these materials, resulting in the dominant Korringa process responsible for the observed relaxation rates.

show abstract

supporting

confidence: 71%

mentioning

confidence: 39%

mentioning

confidence: 99%

See 1 more Smart Citation

Evolution of the pseudogap in Sr1−xYxAl

2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…A similar analysis of the temperature dependence of 1/T 1 T without the cross-relaxation process has been reported in the semimetal CaAl 2−x Si 2+x (Ref. 33) and in the Heusler-type compound Fe 2+x V 1−x Al (Ref. 34).…”

supporting

confidence: 77%

Electronic properties of GeTe and Ag- or Sb-substituted GeTe studied by low-temperatureTe125NMR

et al. 2016

View full text Add to dashboard Cite

We have carried out 125 Te nuclear magnetic resonance (NMR) in a wide temperature range of 1.5 -300 K to investigate electronic properties of Ge50Te50, Ag2Ge48Te50 and Sb2Ge48Te50 from a microscopic point of view. From the temperature dependence of NMR shift (K) and nuclear spin lattice relaxation rate (1/T1), we found that two bands contribute to the physical properties of the materials. One band overlaps the Fermi level providing the metallic state where no strong electron correlations are revealed by Korringa analysis. The other band is separated from the Fermi level by an energy gap of Eg/kB ∼ 67 K, which gives rise to the semiconductor-like properties. First-principle calculation reveals that the metallic band originates from the Ge vacancy while the semiconductor-like band is related to the fine structure of the density of states near the Fermi level. Low-temperature 125 Te NMR data for the materials studied here clearly show that the Ag substitution increases hole concentration while Sb substitution decreases it.

show abstract

“…A well-studied silicide of this type is CaAl 2 Si 2 , a semimetal arising from a slight overlap of one conduction band and two valence bands, with the Fermi level located at the valley of the density of states. Hall coefficient of CaAl 2 Si 2 exhibit sign reversal at around 150 K, indicative of a change of dominant carrier with temperature whereas r(T) is found to be dominated at low-T by intrinsically metallic nature, while at high temperatures, r(T) is attributed to a thermally activated increase in density of hole carriers [9]. The observed phenomena in the transport properties of CaAl 2 Si 2 have been attributed to the semimetallic response, based on both experimental observations and electronic structure calculations [5].…”

Section: Introductionmentioning

confidence: 85%