Study of Coexistence of Ferromagnetism and Superconductivity in Single-Crystal ErRh4B4

Abstract

Neutron-diffraction and bulk resistivity measurements on single crystals of Er${\mathrm{Rh}}_4$ ${\mathrm{B}}_4$ have revealed an intermediate phase below 1.2 K, where both a ferromagnetic structure and a transverse linearly polarized modulated structure, with a wavelength of ∼ 100 Å, are observed. The modulated moment disappears suddenly below 0.71 K, with loss of superconductivity and a transition to a normal ferromagnetic state. The intermediate phase is interpreted as being one of coexisting ferromagnetic domains and superconducting domains.