Fig. 4: Magnetostriction of the surface layer.
From: Emergent exchange-driven giant magnetoelastic coupling in a correlated itinerant ferromagnet
a,b, Change in Δz(H) recorded as the field Bz is ramped from –0.4 T to 0.4 T (a) and back (b) (T = 1.8 K, Vset = 10 mV, Iset = 50 pA). Only a small section of the ramp is shown; the full ramps are shown in Supplementary Fig. 14b. The traces show a small jump when the surface layer switches its magnetization, indicated by the black arrow. c,d, Time traces of the Δz(t) over ~15 s during which the field Bz is ramped by 10 mT from 0.34 T to 0.35 T (c) and from –0.27 T to –0.28 T (d). A jump of ~300 fm can be seen in both traces, marked by a black arrow. The grey-shaded area indicates the time after the switch has happened. The switching of the surface layer is verified from the tunnelling spectra taken before (purple line) and after (red/blue line) the time trace is recorded (insets show the tunnelling parameters for z(H) and z(t) traces, Vset = 10 mV, Iset = 50 pA; for the spectra, Iset = 450 pA, VL = 0.5 mV; Supplementary Fig. 14j,k). e, Histogram of jumps in Δz(t) when the surface layer switches, extracted from 56 magnetostriction curves (Iset = 50 pA, Vset = 10–50 mV).
