Pulsed laser-deposited nanocrystalline GdB6 thin films on W and Re as field emitters
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- 作者：Sachin R. Suryawanshi ; Anil K. Singh ; Deodatta M. Phase…
- 刊名：Applied Physics A: Materials Science & Processing
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：122
- 期：10
- 全文大小：2,917 KB
- 刊物类别：Physics and Astronomy
- 刊物主题：Physics
Condensed Matter
Optical and Electronic Materials
Nanotechnology
Characterization and Evaluation Materials
Surfaces and Interfaces and Thin Films
Operating Procedures and Materials Treatment - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-0630
- 卷排序：122
文摘
Gadolinium hexaboride (GdB6) nanocrystalline thin films were grown on tungsten (W), rhenium (Re) tips and foil substrates using optimized pulsed laser deposition (PLD) technique. The X-ray diffraction analysis reveals formation of pure, crystalline cubic phase of GdB6 on W and Re substrates, under the prevailing PLD conditions. The field emission (FE) studies of GdB6/W and GdB6/Re emitters were performed in a planar diode configuration at the base pressure ~10−8 mbar. The GdB6/W and GdB6/Re tip emitters deliver high emission current densities of ~1.4 and 0.811 mA/cm2 at an applied field of ~6.0 and 7.0 V/µm, respectively. The Fowler–Nordheim (F–N) plots were found to be nearly linear showing metallic nature of the emitters. The noticeably high values of field enhancement factor (β) estimated using the slopes of the F–N plots indicate that the PLD GdB6 coating on W and Re substrates comprises of high-aspect-ratio nanostructures. Interestingly, the GdB6/W and GdB6/Re planar emitters exhibit excellent current stability at the preset values over a long-term operation, as compared to the tip emitters. Furthermore, the values of workfunction of the GdB6/W and GdB6/Re emitters, experimentally measured using ultraviolet photoelectron spectroscopy, are found to be same, ~1.6 ± 0.1 eV. Despite possessing same workfunction value, the FE characteristics of the GdB6/W emitter are markedly different from that of GdB6/Re emitter, which can be attributed to the growth of GdB6 films on W and Re substrates.