Superconducting MgB2 thin films prepared by chemical vapor deposition from diborane

Fu, Xing; Wang, D.S; Zhang, Z.P; Yang, Jinlong

doi:10.1016/s0921-4534(02)01793-8

Cited by 22 publications

(9 citation statements)

References 15 publications

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“…In the early stages the pulsed laser deposition (PLD) method has mostly been used to fabricate MgB 2 films [2][3][4][5][6]. Subsequently, e-beam evaporation [7], molecular beam epitaxy [8,9], sputtering [10,11], and chemical vapour deposition [12] methods have been explored. Due to the extreme difference in the vapour pressures of Mg and B, it is very difficult to maintain an environment for the in situ formation of stoichiometric MgB 2 phase.…”

Section: Introductionmentioning

confidence: 99%

“…Due to the extreme difference in the vapour pressures of Mg and B, it is very difficult to maintain an environment for the in situ formation of stoichiometric MgB 2 phase. Most of the films were made either by ex situ diffusion of Mg in the B precursor film [2,7,10,12] or by in situ annealing [3][4][5][6]11]. Recently, Zeng et al have successfully overcome the extreme disparity of the vapour pressures of Mg and B by adopting a hybrid physico-chemical vapour deposition (HPCVD) technique to obtain in situ epitaxial films [13].…”

Section: Introductionmentioning

confidence: 99%

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Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Lee

Ahn

Kim

et al. 2003

Supercond. Sci. Technol.

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We have studied properties of the superconducting MgB 2 thin films made on sapphire substrates by radio frequency (rf) magnetron co-sputtering of Mg and B. The effects of annealing temperature and Mg:B ratio on the superconducting properties of the film were investigated. Films were prepared by room-temperature co-deposition of Mg and B using two guns and annealed in situ to form the superconducting MgB 2 phase. Ar sputtering pressure was 20 mtorr with 5% of hydrogen gas to trap remnant oxygen gas in the deposition chamber. Average rf power density of Mg target was varied from 2 to 4 W cm −2 with that of B fixed at 12 W cm −2 . An additional Mg layer was deposited on top to make up for Mg loss during in situ annealing. Films were heated up to 500-750 • C at the rate of 60 • C min −1 , annealed for 20 min, and naturally cooled down by turning off the heater. The best results were obtained for films deposited with the rf power of Mg target at 50 W and annealed at 700 • C. The mechanism for MgB 2 formation in low-pressure annealing is believed to be that during annealing the local Mg vapour pressure inside the film falls within the thermodynamic window.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Lee

Ahn

Kim

et al. 2003

Supercond. Sci. Technol.

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“…Diborane–sorbent interactions are also relevant to the development of chemical hydrogen storage strategies. In many proposed hydrogen storage systems, high-surface-area solids are used to control the dehydrogenation of BH x -containing molecules such as ammonia borane (H 3 NBH 3 ), which introduces the potential for unwanted diborane formation. − In these and other applications, − advanced sorbents that target specific interactions with diborane would be greatly beneficial.…”

Section: Introductionmentioning

confidence: 99%

Reversible Dissociation for Effective Storage of Diborane Gas within the UiO-66-NH₂ Metal–Organic Framework

Jones

Gibbons

Morris

et al. 2022

ACS Appl. Mater. Interfaces

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There is an acute need for materials that can store the toxic and highly reactive diborane gas at room temperature. In this work, the interfacial chemistry leading to safe and reversible storage of diborane (B 2 H 6 ) in the UiO-66-NH 2 metal−organic framework (MOF) was investigated via in situ transmission infrared (IR) spectroscopy, temperature-programmed desorption (TPD), and electronic structure calculations. The infrared spectrum of B 2 H 6 adsorbed within UiO-66-NH 2 indicates hydrogen bonding with the μ 3 −OH groups of the MOF nodes and chemisorption at the −NH 2 groups of the MOF linkers. The conversion of physisorbed to chemisorbed diborane, as observed through a spectroscopically unique intermediate species, occurred over a broad temperature regime from 80 to 410 K. During B 2 H 6 -TPD studies, both the weakly and strongly bound species were found to desorb exclusively as molecular B 2 H 6 . Infrared spectroscopic studies, performed during diborane adsorption and reaction, combined with electronic structure calculations, revealed that chemisorption occurred via a reversible dissociation reaction involving a "half-open" B 2 H 6 intermediate and resulted in the formation of two NH 2 -bound BH 3 units, which leave the MOF as B 2 H 6 via recombinative desorption. The close spacing of −NH 2 groups in the UiO-66-NH 2 MOF is key to enabling high-temperature chemisorptive storage of B 2 H 6 , and the spatial arrangement of the amine groups has a significant effect on the dissociation energy profile. This work demonstrates that reversible dissociation of B 2 H 6 on precisely engineered, nucleophile-rich materials represents a promising pathway to diborane stabilization and long-term storage.

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“…Give that the potential advantages of all MgB 2 junctions, with high quality tunnel barriers, to obtain high critical current density J C and multilayers consisting of superconducting, insulating and resistive films, have been established, the primary requirement is an essential fabrication technology [2]. However, fundamental challenges exist under practical conditions, because disorder, nonstoichiometries and contamination occurs during the hightemperature growth of the top MgB 2 electrode (600e850 C) on the oxide or nitride barrier [3,4].…”

Section: Introductionmentioning

confidence: 99%

Fabrication of sandwich-type MgB2/Boron/MgB2 Josephson junctions with rapid annealing method

Song

Wang

Junli

et al. 2015

Journal of Alloys and Compounds

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Superconducting MgB2 thin films prepared by chemical vapor deposition from diborane

Cited by 22 publications

References 15 publications

Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Reversible Dissociation for Effective Storage of Diborane Gas within the UiO-66-NH₂ Metal–Organic Framework

Fabrication of sandwich-type MgB2/Boron/MgB2 Josephson junctions with rapid annealing method

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Superconducting MgB2 thin films prepared by chemical vapor deposition from diborane

Cited by 22 publications

References 15 publications

Properties of MgB2thin films made by radio frequency magnetron co-sputtering

Properties of MgB2thin films made by radio frequency magnetron co-sputtering

Reversible Dissociation for Effective Storage of Diborane Gas within the UiO-66-NH2 Metal–Organic Framework

Fabrication of sandwich-type MgB2/Boron/MgB2 Josephson junctions with rapid annealing method

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Product

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Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Properties of MgB₂thin films made by radio frequency magnetron co-sputtering

Reversible Dissociation for Effective Storage of Diborane Gas within the UiO-66-NH₂ Metal–Organic Framework