Fluence dependent delay of Ni in an FeNi alloy supports an exchange based origin - Jana, Somnath; Knut, Ronny; Singh, Puloma; Yao, Kelvin; Tzschaschel, Christian; Richter, Johanna; Schick, Daniel; Sommer, Denny; Engel, Dieter; Karis, Olof; Schmising, Clemens von Korff; Eisebitt, Stefan (2025)