Fig. 4: Effect of ion migration on the magnetoresistance.

a Temperature-dependent resistivity for oxygen-concentration-controlled GdOx (red and blue symbols) and metallic Gd (green symbol). b Magnetic-field-dependent resistivity of the three samples at 10K. The colors correspond to those in a. c Relationship between 1/ρxx and T−1/2 (the data are replotted from a). The solid lines represent fitting curves based on Eq. (1).