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Imai, Motoharu; Sadki, El Hadi; Abe, Hideki; Nishida, Kenji; Kimura, Takashi; Sato, Taku; Hirata, Kazuto; Kitazawa, Hideaki

doi:10.1103/physrevb.68.064512

Cited by 40 publications

(12 citation statements)

References 44 publications

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“…R H is related to the carrier density n by R H ¼ 1/ne, where e is the elementary charge. In BaAlSi, the carrier density is estimated as 2.1 Â 10 22 cm À3 , which is larger than that in CaAlSi, 8.4 Â 10 21 cm À3 [12]. This again agrees with the band-structure calculations [10] and the resistivity measurements mentioned above.…”

Section: Resultssupporting

confidence: 79%

Comparison of physical properties in BaAlSi and CaAlSi

Sugawara

Sato

Souma

et al. 2006

Science and Technology of Advanced Materials

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CaAlSi, with the AlB 2 -type structure, is a superconductor with relatively high T c of 7.7 K and the related compounds, SrAlSi and BaAlSi have the same crystal structure. Despite the fact that the density of states in SrAlSi and BaAlSi is higher than that of CaAlSi, T c of SrAlSi is 4.2 K and BaAlSi does not show superconductivity down to 2 K. We synthesize polycrystalline and single crystalline BaAlSi and compare their physical properties with those in CaAlSi. The transport and the specific heat measurements show the higher density of states in BaAlSi, consistent with the band structure calculations. We interpret that the absence of superconductivity in BaAlSi is due to the much weaker electron-phonon coupling constant compared with that in CaAlSi, because of the absence of the soft-phonon mode. In the course of the study, we find a superconductor with a composition close to Ba 2 Al 4 Si 3 .

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Section: Resultssupporting

confidence: 79%

Comparison of physical properties in BaAlSi and CaAlSi

Sugawara

Sato

Souma

et al. 2006

Science and Technology of Advanced Materials

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“…On the other hand, a fraction of the Fe at 4j sites might have been substituted by B or Al atoms (even though the measured lattice parameters are very close to those reported for single crystal AlFe 2 B 2 ) [2]. Analogous atomic intermixing was reported to occur in Ca(Al 0.5 Si 0.5 ) 2 [17], and CaAl 2-x Si 2 þ x (jxj o0:25) [18]. Mossbauer Spectra collected at various temperatures.…”

Section: Mossbauer Spectroscopymentioning

confidence: 61%

On the ferromagnetism of AlFe2B2

ElMassalami

Oliveira

Takeya

2011

Journal of Magnetism and Magnetic Materials

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Keywords:AlFe 2 B 2 Ternary compounds Ferromagnet Mossbauer effect spectroscopy Magnetic properties of intermetallic a b s t r a c t Based on extensive Mossbauer effect (ME) and magnetization measurements, the orthorhombic AlFe 2 B 2 was characterized as a ferromagnet (FM) because this character is evident as an onset of a FM transition at T c ¼ 320 K and characteristic magnetizations isotherms below T c . At liquid helium temperatures, the magnetization saturates to m sat % 1m B per Fe atom; a value which is half the one reported for the iron metal indicating a relatively more filled 3d band. The ME analysis revealed a hyperfine field H(0) of 88(2) kOe, an isomer shift (relative to Fe) of 0.50(2) mm/s, and a quadrupole parameter of 0.02 mm/s: all parameters extrapolated to zero Kelvin. The itinerant character of the magnetic moment will be discussed.

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“…[6][7][8] Among these anomalous behaviors, line broadening with increasing temperature might be ascribed by a large anharmonic contribution, while the broad linewidth at low temperatures is not due to anharmonicity but to the strong electron-phonon interaction. 9,10 Important EPC knowledge in MgB 2 obtained by Raman scattering suggests that the similar studies for the analogous intermetallic compounds such as alkaline-earth-intercalated graphite 11 and ternary silicide MAlSi ͑M: alkaline-earth atoms͒ 12,13 are necessary in order to gain an insight into the electron-phonon pairing mechanism of superconductivity as a reference material for MgB 2 .…”

Section: Introductionmentioning

confidence: 99%

Anomalous phonon properties in the silicide superconductors CaAlSi and SrAlSi

et al. 2008

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Lattice-dynamical properties of CaAlSi and SrAlSi with a similar layer structure to MgB 2 have been first investigated by both Raman-scattering and ab initio calculations. All Raman-active phonons with EЈ symmetry have been clearly observed for both compounds. Their line shapes are asymmetric but their linewidths are ϳ10 cm −1 , which is very narrower than that of MgB 2 . In addition to the Raman-active modes, several extra peaks have been observed below 160 cm −1 . These low-energy extra modes can be assigned to the out-of-plane vibrations of Al perpendicular to Al-Si basal plane. Since these peak intensities are strongly affected by the incident energy ͑resonance Raman process͒, the electronic state is important for them. Moreover, in both crystals of CaAlSi and SrAlSi, we point out the energy difference for the different propagation directions along the c axis and the c plane, in spite of the very close wave vector to the Brillouin-zone center. This energy difference cannot be explained by a usual Raman-scattering scenario at this stage.

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Superconducting properties of single-crystallineCa(Al0.5,Si0.5

Cited by 40 publications

References 44 publications

Comparison of physical properties in BaAlSi and CaAlSi

Comparison of physical properties in BaAlSi and CaAlSi

On the ferromagnetism of AlFe2B2

Anomalous phonon properties in the silicide superconductors CaAlSi and SrAlSi

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