Hall effect and magnetoresistance in UNiSn

Diehl, J.; Fischer, Hélène; Köhler, R.; Geibel, C.; Steglich, F.; Maeda, Y.; Takabatake, Toshiro; Fujii, H.

doi:10.1016/0921-4526(93)90680-5

Cited by 17 publications

(5 citation statements)

References 5 publications

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“…The fitting value of E a is 0.265 eV, which is close to the values of thermal activation energy found in other Heusler alloys [33,34]. As an isostructural compound with NiMnAs, UNiSn also showed a similar crossover from the semiconducting behaviour to metallic behaviour, and the thermal activation energy was found to be 0.105-0.12 eV [34,35]. It was proposed that there was a pseudogap in the electronic states around the Fermi level, and this energy gap would be destroyed by the spin polarization below T C , resulting in the presence of metallic behaviour [36].…”

Section: Magneto-transport Properties Of Ni 104 Mn 096 As Filmsupporting

confidence: 81%

Magneto-transport properties of cubic NiMnAs film epitaxied on GaAs (110) substrate

Wei¹,

Wang²,

Ma³

et al. 2021

J. Phys.: Condens. Matter

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The magneto-transport properties of cubic NiMnAs film epitaxied on the GaAs (110) substrate are investigated. The x-ray diffraction measurements reveal that the NiMnAs (111) crystal plane is parallel to the GaAs (110) crystal plane. The temperature dependence of resistivity at high temperature can be described by a thermal activation model, from which the thermal activation energy is obtained and found to be comparable with many other Heusler alloys. By fitting the temperature dependence of resistivity at low temperature, the coefficient of the quadratic temperature term is determined to be 1.34 × 10 −3 μΩ cm K −2 . This value suggests the possible presence of single-magnon scattering in the NiMnAs film. The negative magnetoresistance is attributed to the suppression of the spin-dependent scattering, which would not take place in a half-metal. The angle dependence of the anisotropic magnetoresistance (AMR) is measured, and the AMR ratios are positive even at low temperature. These magneto-transport properties indicate that the predicted half-metallicity is destroyed in the NiMnAs film. The absence of the half-metallicity may be attributed to the atomic disorder in the NiMnAs lattice, which needs to be confirmed by further experimental and theoretical studies.

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Section: Magneto-transport Properties Of Ni 104 Mn 096 As Filmsupporting

confidence: 81%

Magneto-transport properties of cubic NiMnAs film epitaxied on GaAs (110) substrate

Wei¹,

Wang²,

Ma³

et al. 2021

J. Phys.: Condens. Matter

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“…The Gaussian function was used to simulate the instrumental resolution. The effects of the lifetime broadening and the photoemission matrix elements were not included in the theory curves [38] 7 . At the bottom panels, the theoretical spectra correspond to the sum of the U d, T d and Sn p PDOS, because none of the contributions are negligible at hν = 22 eV and it is difficult to separate them out (see the discussion under figure 1).…”

Section: Comparison To the L S D A + U Calculationmentioning

confidence: 99%

“…Both UNiSn and UPdSn exhibit interesting phase transitions with the antiferromagnetic (AF) ground states. UNiSn displays an AF order below the Neel temperature T N ≃ 43 K, a structural transition from the cubic symmetry to the tetragonal symmetry at T N 5 , and a semiconductor-to-metal (S-M) transition around T MI ∼ 55 K 6,7 . This multiple phase transition seems to be anomalous because it is an inverse metalinsulator transition with a gap-opening above T N and the structural, S-M, and AFM transitions occur concomitantly.…”

Section: Introductionmentioning

confidence: 99%

Electronic structures of UTSn (T = Ni, Pd) using photoemission spectroscopy

Kang¹,

Wi²,

Kim³

et al. 2004

J. Phys.: Condens. Matter

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The electronic structures of the localized 5f systems UTSn (T=Ni, Pd) have been investigated using photoemission spectroscopy (PES). The extracted U 5f PES spectra of UTSn (T=Ni, Pd) exhibit a broad peak centered at ∼ 0.3 eV below EF with rather small spectral weight near EF (N f (EF)). The small N f (EF) in UTSn is found to be correlated with the T d PES spectra that have a very low density of states (DOS) near EF. The high-resolution PES spectra for UTSn provide the V-shaped reduced metallic DOS near EF but do not reveal any appreciable changes in their electronic structures across the magnetic phase transitions. A possible origin for the reduced N f (EF) in UTSn is ascribed to the hybridization to the very low T d DOS at EF. Comparison of the measured PES spectra to the LSDA+U band structure calculation reveals a reasonably good agreement for UPdSn, but not so for UNiSn.

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“…In the paramagnetic region, the exponential rise in ðTÞ towards T N has been associated with activation-type behaviour with an energy gap of magnitude 70-120 meV for UNiSn (Palstra et al 1987, Tran andTroc´1991), which is completely closed just below T N . This semiconductor-to-metal transition manifests itself as a precipitous drop in ðTÞ and a large increase in the carrier density (Diehl et al 1993). In addition, there is a structural transition from the cubic MgAgAs lattice (T > T N ) to a tetragonal lattice symmetry (T < T N ) (Akazawa et al 1996) with an accompanying quadrupolar ordering (Akazawa et al 1998, McEven et al 2000.…”

mentioning

confidence: 96%