Antiferromagnetic Resonance in CoF2, NiF2, and MnCO3

Abstract

The far‐infrared transmission spectra of CoF₂, NiF₂, and MnCO₃ have been measured from 3 to 100 cm⁻¹ using the techniques of Fourier‐transform interferometry. Antiferromagnetic resonance branches have been found in CoF₂ at 28.5 cm⁻¹ and 36 cm⁻¹ at temperature T≈0, each of which splits in a magnetic field along the c axis. These resonances have been studied as a function of field, temperature, and uniaxial stress. Antiferromagnetic resonance at 31.1 cm⁻¹ and ferromagnetic resonance at 3.33 cm⁻¹ in NiF₂ at T≈0 have been studied as a function of field and temperature, and the results are compared with Moriya's theory. Antiferromagnetic resonance has been observed at 4.13 cm⁻¹ in MnCO₃ at T≈0.