Fig. 4: Spatial correlation between superconducting transitions and structural domains in (La_0.9Y_0.1)H₁₀ at 153 GPa.

A–D Temperature-dependent four-probe partial resistance traces (R_ab,cd) measured using eight current–voltage configurations are grouped into four panels corresponding to distinct current paths: A R_12,34 and R_12,43; B R_34,12 and R_43,21; C R_23,41 and R_23,14; D R_41,23 and R_41,32. Each plot includes a schematic of the corresponding current path overlaid on the composite XDI map, highlighting the spatial distribution of cubic \({Fm}\bar{3}m\) (red) and hexagonal \(P{6}_{3}/{mmc}\) (blue) phases. Electrode positions and current directions are annotated. Configurations that differ only by voltage polarity (e.g., R_34,12 vs. R_34,21) are spatially equivalent; for clarity, only one representative XDI map is shown for each pair. Partial resistance traces corresponding to current paths intersecting FCC-enriched domains (e.g., R_34,12, R_41,23) exhibit sharp superconducting transitions near 240 K with narrow widths (ΔT  < 10 K). In contrast, broader or multi-step transitions are observed in configurations that sample mixed-phase or HCP-dominated regions (e.g., R_12,34, R_23,14), with onsets near 241 and 218 K. We note that due to single permutations inability to account for voltage drops due to the Seebeck effect, partial resistances exhibit negative values below T_c⁴⁹. Averaging reverse-biased polarities corrects for this instrumental artifact, causing an apparent drop to zero resistance. These observations establish a direct spatial correlation between local structural heterogeneity and superconducting behavior.