Electronic structures and properties of lanthanide hexaboride nanowires

Lu Wang, Guangfu Luo, Daniel Valencia, Carlos H. Sierra Llavina, Renat F Sabirianov, Jing Lu, Jun Qiang Lu, Wai Ning Mei, Chin Li "Barry" Cheung

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The promising usage of lanthanide hexaboride nanowires as excellent electron emitter materials is generally attributed to the intrinsic low work functions of their bulk counterparts. Most analytical models for the field enhanced electron emission phenomenon adopt an underlying presumption of little or no change to the work function of the emission materials at the nanoscale. However, such a presumption is difficult to experimentally verify because current analytical models often employ empirical parameters such as the geometrically enhancement factors and the actual field emission areas are hard to determine. Herein, we report our density functional theory study of the size-dependence and element-specificity of the electronic structures and work functions of infinitely long lanthanide hexaboride nanowires constructed with n × n × ∞ unit cells (n = 1, 2, 3, and 4). Our modeling results reveal that the distinguished metal-like electronic properties and the low work function values of the sides of most examined nanowire systems are due to the abundant 4f and 5d states from the lanthanide metal atoms positioned at the Fermi level. These work function values are found to be weakly wire-size-dependent and element-dependent across the lanthanide series. They approach to the bulk values when their lateral wire-sizes are at or above 4-unit cell wide. The presence of abundance states at the Fermi level is found to be a common feature to rationalize the work functions of reported hexaboride systems.

Original languageEnglish (US)
Article number143709
JournalJournal of Applied Physics
Volume114
Issue number14
DOIs
StatePublished - Oct 14 2013

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nanowires
electronic structure
wire
cells
metals
electron emission
field emission
emitters
density functional theory
augmentation
electronics
atoms
electrons

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Electronic structures and properties of lanthanide hexaboride nanowires. / Wang, Lu; Luo, Guangfu; Valencia, Daniel; Sierra Llavina, Carlos H.; Sabirianov, Renat F; Lu, Jing; Lu, Jun Qiang; Mei, Wai Ning; Cheung, Chin Li "Barry".

In: Journal of Applied Physics, Vol. 114, No. 14, 143709, 14.10.2013.

Research output: Contribution to journalArticle

Wang, L, Luo, G, Valencia, D, Sierra Llavina, CH, Sabirianov, RF, Lu, J, Lu, JQ, Mei, WN & Cheung, CLB 2013, 'Electronic structures and properties of lanthanide hexaboride nanowires', Journal of Applied Physics, vol. 114, no. 14, 143709. https://doi.org/10.1063/1.4824285
Wang, Lu ; Luo, Guangfu ; Valencia, Daniel ; Sierra Llavina, Carlos H. ; Sabirianov, Renat F ; Lu, Jing ; Lu, Jun Qiang ; Mei, Wai Ning ; Cheung, Chin Li "Barry". / Electronic structures and properties of lanthanide hexaboride nanowires. In: Journal of Applied Physics. 2013 ; Vol. 114, No. 14.
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