Submillimeter spectroscopy of the magneto- and electrodipolar excitations in rare-earth orthoferrites

Abstract

We have investigated magneto- and electrodipolar excitations within the Tm³⁺ ion ground multiplet in TmFeO₃ orthoferrite. The temperature dependences of the resonance frequencies, the linewidths and the mode contributions to the static magnetic permeability and dielectric permittivity were derived. An increase (up to 30%) of the quasistatic dielectric permittivity along the c-axis was observed at low T resulting from an appreciable contribution of the electrodipolar rare-earth modes in Tm³⁺.

Key Words:

• Rare-earth ion
• magnetodipolar and electrodipolar electron transitions
• orthoferrite.