Coexistence of Superconductivity and Magnetism in EuFe$_{2}$(As$_{0.7}$P$_{0.3}$ )$_{2}$

We have performed resistivity, magnetization, and $\mu $SR studies on single crystalline EuFe$_{2}$(As$_{0.7}$P$_{0.3}$)$_{2}$. These measurements provide clear evidence for bulk superconductivity in this system, with the sample resistance dropping to zero around 12 K. This work has also revealed ferromagnetic ordering of the S = 7/2 Eu$^{2+}$ moments along the c-axis (T$_{curie} \quad \sim $ 19 K). Finally, our $\mu $SR results indicate that the Eu magnetism is very homogeneous and occupies the full-volume fraction, pointing to real-space coexistence of magnetism and superconductivity in this material.