Large magnetic saturation field in the antiferromagnet EuIrSi3

We report a saturation magnetic field of 41 T at 4.2 K in the antiferromagnet EuIrSi ₃ ( T _N = 51.8 K), much larger than the values in typical S-state (net orbital state, L = 0) magnetic systems but consistent with the mean-field theory. We interpret this anomalous behaviour in conjunction with a higher density of states of conduction electrons in EuIrSi ₃ compared to other isostructural members in the Eu TX ₃ ( T = Ni, Pt, Rh, Ir; X = Si, Ge) homologous series. Moreover, low-temperature isothermal magnetization indicates spin orientation occurring at fields 13 T and 33 T, respectively. A magnetic phase diagram by aid of pulsed-field magnetization and magnetoresistivity measurements of EuIrSi ₃ is constructed.