Neutron Scattering Study of Magnetic Ordering in the Reentrant Superconductor ErRh4B4

Abstract

Using neutron scattering techniques, we show that the destruction of superconductivity in Er${\mathrm{Rh}}_4$ ${\mathrm{B}}_4$ at $T_{c2\mathrm{}}=1.0\mathrm{}$ K is accompanied by the development of long-range ferromagnetic ordering of the Er sublattice. The observed magnetic Bragg intensities indicate that the Er ion has a moment of 5.6${\mathrm{\mu }}_{\mathrm{B}}$ which is oriented in the tetragonal basal plane. The magnetic transiton appears second order, but shows anomalously strong precursor scattering.