Fig. 3: Depth-dependent magnetism in Cs(V_0.93Nb_0.07)₃Sb₅ (Nb_0.07-CVS).

a Muon implantation profile simulated for several energies. b Zero-field (ZF) muon-spin rotation (μSR) spectra for Nb_0.07-CVS. obtained at 5 K at the surface (mean implantation depth, \(\bar{z}=10\,{\rm {nm}}\), green) and in the bulk (\(\bar{z}=100\,{\rm {nm}}\), purple). The error bars are the standard error of the mean (s.e.m.) in about 10⁶ events. c Temperature dependence of the relaxation rate, Γ measured in 50 G and zero-field at the surface (\(\bar{z}=10\,{\rm {nm}}\), green), and zero-field in the bulk (\(\bar{z}=100\,{\rm {nm}}\), purple). The high-temperature relaxation rate has been subtracted to put all data on a comparable scale. The error bars represent the standard deviation of the fit parameters. d The zero-field muon-spin relaxation rate measured at 5K in an applied field of 5 mT as a function of muon implantation energy, E. Top axis shows the mean implantation depth, \(\bar{z}\). Green to purple shading depicts the transition from near-surface to bulk behaviour.