Fig. 1. Zero-field (ZF) μSR time spectra.

Time evolution of zero-field muon spin polarization P_ZF(t) = $A_{ZF}^{\mathrm{GKT}}\left(t\right)/A_0$, measured above and below T_c for Ir_1−δSb (a), synthesized at 5.5 GPa and for Ir_1−xRh_xSb with x = 0.3 (b). Error bars are the standard error of means (s.e.m.) in about 10⁶ events. The error of each bin count n is given by the standard deviation (s.d.) of n. The errors of each bin in P_ZF(t) are then calculated by standard error (s.e.) propagation. The solid lines represent fits to the data by means of equation (1). The inset in panel a displays the temperature dependence of the zero-field muon spin relaxation rate Δ_ZF across T_c ≃ 4.0 K.