Interaction between magnetic order and the vortex lattice in HoNi2B2C

Local Hall probe array magnetization measurements have been made on single crystals of the magnetic superconductor HoNi2B2C. Measured flux profiles show that surface barriers dominate the hysteresis below T-c(similar or equal to 8.9K) except in a narrow temperature range between 5 and 5.75 K where superconductivity is strongly suppressed due to the onset of an a-axis incommensurate ordering of the Ho moments. The data presented show that the magnetic order also has a profound influence on the nonequilibrium (vortex-pinning) properties of the superconducting state