1. Effects of magnetic and non-magnetic doping on the vortex lattice in MgB2.
- Author
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Louden, Elizabeth R., Manni, Soham, Van Zandt, Judah E., Leishman, Allan W. D., Taufour, Valentin, Bud'ko, Sergey L., DeBeer-Schmitt, Lisa, Honecker, Dirk, Dewhurst, Charles D., Canfield, Paul C., and Eskildsen, Morten R.
- Subjects
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SMALL-angle neutron scattering , *CRITICAL temperature , *PHASE diagrams , *ELECTRONIC structure , *SUPERCONDUCTIVITY , *MAGNETIC fields - Abstract
Small-angle neutron scattering has been used to study the vortex lattice in superconducting MgB2 doped with either manganese or carbon to achieve a similar suppression of the critical temperature. Measurements were performed with the magnetic field applied along the c axis, where the vortex lattice in pure MgB2 is known to undergo a field- and temperature-driven 30° rotation transition. For Mn doping, the vortex lattice phase diagram remains qualitatively similar to that of pure MgB2, indicating only a modest effect on the vortex-- vortex interaction. In contrast, the vortex lattice rotation transition is completely suppressed in the C-doped case, probably due to a change in the electronic structure which affects the two-band/two-gap nature of superconductivity in MgB2. The vortex lattice longitudinal correlation length shows the opposite behavior, remaining roughly unchanged between pure and C-doped MgB2 while it is significantly reduced in the Mn-doped case. However, the extensive vortex lattice metastability and related activated behavior, observed in conjunction with the vortex lattice transition in pure MgB2, are also seen in the Mn-doped sample. This shows that the vortex lattice disordering is not associated with a substantially increased vortex pinning. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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