Vortex Matter in Highly Strained Nb xmlns:search="http://marklogic.com/appservices/search">\(_{75}\) Zr xmlns:search="http:

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• 作者：Jagdish Chandra ; Meghmalhar Manekar ; V. K. Sharma…
• 关键词：Vortex matter ; Collective pinning ; Viscous flow
• 刊名：Journal of Low Temperature Physics
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：186
• 期：1-2
• 页码：21-43
• 全文大小：
• 刊物类别：Physics and Astronomy
• 刊物主题：Condensed Matter Physics; Characterization and Evaluation of Materials; Magnetism, Magnetic Materials;
• 出版者：Springer US
• ISSN：1573-7357
• 卷排序：186

文摘

We present the results of magnetization and magneto-transport measurements in the superconducting state of an as-cast Nb\(_{75}\)Zr\(_{25}\) alloy. We also report the microstructure of our sample at various length scales by using optical, scanning electron and transmission electron microscopies. The information of microstructure is used to understand the flux pinning properties in the superconducting state within the framework of collective pinning. The magneto-transport measurements show a non-Arrhenius behaviour of the temperature- and field-dependent resistivity across the resistive transition and is understood in terms of a model for viscous flow of disordered solids which is popularly known as the ‘shoving model’. The activation energy for flux flow is assumed to be mainly the elastic energy stored in the flux-line lattice. The scaling of pinning force density indicates the presence of two pinning mechanisms of different origins. The elastic constants of the flux-line lattice are used to estimate the length scale of vortex lattice movement, or the volume displaced by the flux-line lattice. It appears that the vortex lattice displacement estimated from elastic energy considerations is of the same order of magnitude as that of the flux bundle hopping length during flux flow. Our results could provide possible directions for establishing a framework where vortex matter and glass-forming liquids or amorphous solids can be treated in a similar manner for understanding the phenomenon of viscous flow in disordered solids or more generally the pinning and depinning properties of elastic manifolds in random media. It is likely that the vortex molasses scenario is more suited to explain the vortex dynamics in conventional low-T\(_C\) superconductors.