High-pressure phase diagram of ferromagnetic superconductor Eu(Fe_0.75Ru_0.75)₂As₂

Eu(Fe_0.75Ru_0.75)₂As₂ is an intriguing system with unusual coexistence of superconductivity (T_C ~23 K) and ferromagnetism (T_m ~ 20 K) and provide a unique platform to study of the nature of such coexistence. To establish a microscopic magnetic phase diagram of the recent doped 122-type ferromagnetic superconductor Eu(Fe_0.75Ru_0.75)₂As₂, time-resolved synchrotron Mössbauer experiments ¹⁵¹Eu have been performed on a single crystalline sample under hydrostatic pressures and low temperatures. Under compression, the magnetic ordering temperature first increase sharply from 22 K at ambient pressure to 53 K at 10 GPa. With further compression, the magnetic ordering temperature decreases and the magnetic order is fully suppressed above 25.2 GPa. Evolution of the magnetic state with pressure will be discussed in detail.