Fig. 1: Magnetic characterisation of EuFe2(As1−xPx)2 samples.
From: Magnetically controlled vortex dynamics in a ferromagnetic superconductor
a Schematic phase diagram of EuFe2(As1−xPx)2 with approximate positions of samples S1, S2, and SD indicated, after refs. 17,21. b Crystal structure of EuFe2(As1−xPx)2 with direction of Eu moments indicated by green arrows for x ≈ 0.2. c Zero-field-cooled (ZFC) and field-cooled (FC) measurements of magnetisation for S1 (solid blue and dash-dot green) and SD (dashed orange), in applied magnetic fields of 10 Oe and 5 Oe respectively, oriented parallel to the c-axis. Arrows indicate the superconducting critical temperature Tc and ferromagnetic ordering temperature TFM. d ZFC (solid red) and FC (dash-dot purple) measurements of S2 measured under the same conditions as S1 in (c). e Temperature dependence of the susceptibility \(\chi =\frac{dM}{dH}{| }_{M = 0}\) as determined from MHLs for S1 (blue circles) and S2 (green diamonds). The vertical, dotted grey line indicates TFM. Inset: example MHLs from S1 at various fixed temperatures. f Coercive field Hc (M(Hc) = 0) for S1 (blue circles) and S2 (green diamonds), as determined from MHLs. Inset shows expanded view of data in the range 15–23 K to highlight peak in Hc(T) for S1 near TFM.
