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The Dendritic magnetic avalanches in carbon-free MgB$_2$ thin films with and without a deposited Au layer

Eun-Mi Choi·Hyun-Sook Lee·Hyun Jung Kim·Byeongwon Kang·Sung-Ik Lee·A. A. F. Olsen·D. V. Shantsev·T. H. Johansen
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Abstract

From the magneto optics images (MOI), the dendritic magnetic avalanche is known to appear dominantly for thin films of the newly discovered MgB$_2$. To clarify the origin of this phenomenon, we studied in detail the MOI of carbon-free MgB$_2$ thin films with and without a deposited gold layer. The MOI indicated carbon contamination was not the main source of the avalanche. The MOI clearly showed that the deposition of metallic gold deposition on top of a MgB$_2$ thin film improved its thermal stability and suppressed the sudden appearance of the dendritic flux avalanche. This is consistent with the previous observation of flux noise in the magnetization.

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Eun-Mi Choi, Hyun-Sook Lee, Hyun Jung Kim, Byeongwon Kang, Sung-Ik Lee, A. A. F. Olsen, D. V. Shantsev, T. H. Johansen. 2005-04-07. The Dendritic magnetic avalanches in carbon-free MgB$_2$ thin films with and without a deposited Au layer. https://doi.org/10.1063/1.2084323

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