The Entropy Mystery of Fe68Pd32: Solving the Puzzle of Vanishing Expansion - Elena Priesen Reis

This research investigates the century-old Invar effect in iron–palladium alloys under extreme pressure. Using synchrotron experiments and thermodynamic analysis, the study shows that magnetic entropy and vibrational entropy precisely counterbalance each other, eliminating thermal expansion. The findings reveal strong spin-phonon coupling as a key mechanism underlying pressure-induced Invar behavior.