Antiferromagnetic Resonance Truncated by the Spin-Flop Transition

Abstract

Antiferromagnetic resonance truncated by the magnetic spin-flop transition at the thermodynamic critical field has been observed in GdAl${\mathrm{O}}_{3}$. Because of the new phenomenon of truncation resulting from the finite linewidth of the resonances, the first-order nature of the transition is directly observable and the superheating can be determined quantitatively.