Antiferromagnetic Resonance inLaMnO3at Low Temperature

Abstract

The antiferromagnetic resonance modes have been studied on a stoichiometric single crystal of ${\mathrm{L}\mathrm{a}\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$ well below the N\'eel temperature, with a static magnetic field along all three crystallographic directions. A canted antiferromagnet model, with biaxial anisotropy and a Dzyaloshinski-Moriya (DM) interaction, explains the results. The DM interaction, often cited as the dominant cause of the canted magnetism, is found to be weak. Instead, the ${\mathrm{G}\mathrm{d}\mathrm{F}\mathrm{e}\mathrm{O}}_{3}$-type octahedron rotation leads to the tilted character of the single-ion anisotropy that plays a dominant role in spin canting.