Interplay of local-moment ferromagnetism and superconductivity in ErRh 4B4 single crystals

Abstract

Tunnel-diode resonator technique was used to study crystals of ferromagnetic reentrant superconductor, ErRh4B4. At the boundary between ferromagnetism (FM) and superconductivity (SC), dynamic magnetic susceptibility, χ(T,H), exhibits highly asymmetric behavior upon warming and cooling as well as enhanced diamagnetism on the SC side. SC phase nucleates upon warming in a cascade of discontinuous jumps in magnetic susceptibility χ(T,H), whereas FM phase develops gradually as reported in detail in [1]. Here we further investigate enhanced diamagnetism. We find that when a magnetic field is applied along the magnetic easy axes, a region of enhanced diamagnetic screening is smaller than in the perpendicular orientation. A discussion of possible causes of this effect is provided. Date: 15 June 2008 © 2009 IOP Publishing Ltd.