Phase diagram and low temperature magnetization of Gd xY 1−xRh 4B 4

Abstract

The phase diagram of Gd xY 1−xRh 4B 4 between the paramagnetic, superconducting and ferromagnetic state is reported. Low temperature dc-magnetization measurements reveal that macroscopic electro-magnetic effects are of minor importance for the suppression of H c2, which shows a smooth bell-shaped behavior for x ⩾ 0.15 with no indication of an anomaly near T c2. At low temperature in samples with x ⩾ 0.20 a transition from type II to type I superconductivity seems to occur. The low temperature normal state susceptibility follows a Curie-Weiss law indicating reentrant behavior for x ⩾ 0.10.