Muon-spin rotation and magnetization studies of chemical and hydrostatic pressure effects in EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$

The magnetic phase diagram of EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was investigated by means of magnetization and muon-spin rotation studies as a function of chemical (isovalent substitution of As by P) and hydrostatic pressure. The magnetic phase diagrams of the magnetic ordering of the Eu and Fe spins with respect to P content and hydrostatic pressure are determined and discussed. The present investigations reveal that the magnetic coupling between the Eu and the Fe sublattices strongly and similarly depends on chemical and hydrostatic pressure. Their impact on the occurrence of superconductivity in EuFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ is discussed.