Superconductivity, magnetic ordering, and its interplay in HoNi2B2C

We investigated the low-temperature properties of polycrystalline HoNi_2^11B_2C by means of ac-susceptibility and neutron powder diffraction in the temperature range of 1.5 to 10 K and zero magnetic field. A sample with pronounced re-entrant behaviour was chosen since it exhibits a superconducting state which is strongly affected by the intrinsic magnetism, the formation of long range magnetic order, via pair-breaking. The evolution and volume fractions of the three different magnetic structures were observed and correlated to the superconducting behaviour.