We present small angle neutron scattering studies of the vortex lattice (VL) in CeCoIn5 with magnetic fields applied parallel (H) to the antinodal [100] and nodal [110] directions. For H || [100], a single VL orientation is observed, while a 90 degree reorientation transition is found for H || [110]. For both field orientations and VL configurations we find a distorted hexagonal VL with an anisotropy, Gamma = 2.0 +/- 0.05. The VL form factor shows strong Pauli paramagnetic effects similar to what have previously been reported for H || [001]. At high fields, above which the upper critical field (Hc2) becomes a first-order transition, an increased disordering of the VL is observed.
Cite
@article{arxiv.1201.1880,
title = {Vortex lattice studies in CeCoIn5 with H perpendicular to c},
author = {P. Das and J. S. White and A. T. Holmes and S. Gerber and E. M. Forgan and A. D. Bianchi and M. Kenzelmann and M. Zolliker and J. L. Gavilano and E. D. Bauer and J. L. Sarrao and C. Petrovic and M. R. Eskildsen},
journal= {arXiv preprint arXiv:1201.1880},
year = {2012}
}