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Measuring the Penetration Depth Anisotropy in MgB$_2$ using Small-Angle Neutron Scattering

D. Pal·L. DeBeer-Schmitt·T. Bera·R. Cubitt·C. D. Dewhurst·J. Jun·N. D. Zhigadlo·J. Karpinski·V. G. Kogan·M. R. Eskildsen
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Abstract

Using small-angle neutron scattering we have measured the misalignment between an applied field of 4 kOe and the flux-line lattice in MgB$_2$, as the field is rotated away from the c axis by an angle $θ$. The measurements, performed at 4.9 K, showed the vortices canting towards the c axis for all field orientations. Using a two-band/two-gap model to calculate the magnetization we are able to fit our results yielding a penetration depth anisotropy, $\glam = 1.1 \pm 0.1$.

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D. Pal, L. DeBeer-Schmitt, T. Bera, R. Cubitt, C. D. Dewhurst, J. Jun, N. D. Zhigadlo, J. Karpinski, V. G. Kogan, M. R. Eskildsen. 2006-02-13. Measuring the Penetration Depth Anisotropy in MgB$_2$ using Small-Angle Neutron Scattering. https://doi.org/10.1103/physrevb.73.012513

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