We review studies of the interactions between magnetic order and the flux line lattice (FLL) in the (RE)Ni2B2Cintermetallic borocarbides for (RE)=Tm and Er using small angle neutron scattering (SANS) and magneto-transport. For (RE)=Tm the magnetic order and the FLL assume a common symmetry, sharing a phase transition at ∼2 kOe, despite an order of magnitude difference in periodicity. For (RE)=Er, the penetration depth λ and the coherence length ξ, both of which are derived from the FLL form factor, are modified near TN=6 K by a theoretically predicted weakly divergent pairbreaking. Finally, below 2.3 K, (RE)=Er shows a coexistence of weak ferromagnetism and superconductivity. This state reveals a highly disordered FLL and a striking increase in the critical current, both arising from the strong ferromagnetic pairbreaking.
Available at: http://works.bepress.com/paul_canfield/57/