Field emission and photofield emission energy distributions from LaB6

Mogren, S.; Reifenberger, R.

doi:10.1016/0039-6028(91)90649-d

Cited by 10 publications

(3 citation statements)

References 26 publications

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“…Already, before 1976, values ranging from 2.3 up to 3.2 eV were published for the (001) surface according to Yamauchi . Later reports of Aono et al, Mogren et al, Marchenko et al, Waldhauser et al, and Kawanowa et al present work functions of, respectively, 2.1, 3.3, 2.5, >2.6, and 2.3 eV.…”

Section: Introductionmentioning

confidence: 97%

Ab Initio and Work Function and Surface Energy Anisotropy of LaB₆

2006

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Lanthanum hexaboride is one of the cathode materials most used in high-power electronics technology, but the many experimental results do not provide a consistent picture of the surface properties. Therefore, we report the first ab initio calculations of the work functions and surface energies of the (001), (011), (111), (112), and (012) surfaces by considering the different surface terminations and structural relaxation. Either the (111)B- or the (001)La-terminated surface is the most stable, depending on La chemical potential. The work function of the latter is the lowest (2.07 eV) of the surfaces considered. Both the work function and surface energy decrease further when surface La is replaced by Ba and become, respectively, 1.43 and 7.7 eV/nm(2) at the chemical potentials of elemental lanthanum and barium bulk. These results compare favorably with previous work on the intermetallics BaAl(4), CaAl(4), and BaAuIn(3). Their most stable surfaces possess the lowest work function. Now, we study a compound with a decidedly different crystal type and with its constituting elements from column 3 of the periodic table, of which one is nonmetallic.

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Section: Introductionmentioning

confidence: 97%

Ab Initio and Work Function and Surface Energy Anisotropy of LaB₆

2006

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“…We note that that the absorption length of the laser light is small for light above the band gap, however the diffusion length of electrons can be several microns. Previous work on this system suggests that surface electron diffusion accounts for charge transport [7] [8]. This same work has also compared field and photo-field emission and reported increases of !…”

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confidence: 69%

Monchromatic Photo-Field Electron Emission Sources

et al. 2006

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“…The 0.1-eV and 2.4-eV energies were chosen in order to test the extremes (assuming a photon energy hv = 4.8 eV and a LaB6 work function φ = 2.4 eV), while 1.76 eV was derived as the average initial energy using a free-electron model with a step potential and approximating photoemission by shifting the electronic distribution by hv. 10,11 Momentum was distributed along a profile varying as the cosine of the angle between the wave vector and the normal to the surface, and pulse duration was calculated 2.5 ns after photoexcitation. For each of the energies, the packet duration as a function of emission spot size (i.e., UV probe-laser spot size on the cathode) was simulated for two Wehnelt apertures: a standard 0.7-mm diameter aperture and a larger 1.0-mm diameter aperture.…”

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confidence: 99%