Figure 2

EXAFS fits and result of the bond distances vs. T.
(a) Experimental (black circles) and fit (red lines) EXAFS oscillations of As-Fe (upper curve) and Fe-Fe (lower panel) shells, respectively, for the 54Fe-sample at RT. (b) Temperature dependence of Fe-As bond distances and Fe-Fe bond distances for the 54Fe- and the \\Fe-samples, respectively.