Abstract

We report a new method for synthesizing magnesium diboride (MgB 2) thin films which exhibit a steep increase in the slope of the upper critical field Hc2 versus decreasing temperature (i.e. |dH c2/dT|Tc|≈2.5 T K-1). An Hc2 of 38.4 T at 4.2 K and an extrapolated value of Hc2(0) above 43 T at 0 K are reported. Films of magnesium plus boron were deposited on unheated c-plane sapphire substrates by co-evaporation, and were subsequently annealed in a reducing atmosphere at temperatures below 600 °C. The use of a combination of a magnesium-rich stoichiometry (Mg/B>1/2) for the as-deposited film and a two-step annealing process was found to be critical in obtaining these high values of Hc2 and |dHc2/dT|Tc|.

Original languageEnglish (US)
Article number085009
JournalSuperconductor Science and Technology
Volume21
Issue number8
DOIs
StatePublished - Aug 1 2008

Fingerprint

Magnesium
magnesium
Thin films
Boron
Aluminum Oxide
thin films
Stoichiometry
Evaporation
Annealing
Sapphire
Temperature
stoichiometry
sapphire
boron
Substrates
evaporation
slopes
atmospheres
annealing
temperature

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

A novel technique for synthesizing MgB2 thin films with high upper critical fields. / Shen, Y.; Gandikota, R.; Singh, Rakesh; Hunte, F. L.; Jaroszynski, J.; Larbalestier, D. C.; Rowell, J. M.; Newman, Nathan.

In: Superconductor Science and Technology, Vol. 21, No. 8, 085009, 01.08.2008.

Research output: Contribution to journalArticle

Shen, Y, Gandikota, R, Singh, R, Hunte, FL, Jaroszynski, J, Larbalestier, DC, Rowell, JM & Newman, N 2008, 'A novel technique for synthesizing MgB2 thin films with high upper critical fields', Superconductor Science and Technology, vol. 21, no. 8, 085009. https://doi.org/10.1088/0953-2048/21/8/085009
Shen, Y. ; Gandikota, R. ; Singh, Rakesh ; Hunte, F. L. ; Jaroszynski, J. ; Larbalestier, D. C. ; Rowell, J. M. ; Newman, Nathan. / A novel technique for synthesizing MgB2 thin films with high upper critical fields. In: Superconductor Science and Technology. 2008 ; Vol. 21, No. 8.
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AU - Larbalestier, D. C.

AU - Rowell, J. M.

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