Electric-dipole and magnetic absorption in TbFeO3 single crystals in the THz-IR range

Various mechanisms of absorption including both electric-dipole excitations and magnetic ones in a broadband (5-5000 cm(-1)) polarized transmission and reflection spectra were studied in orthoferrite TbFeO3 using a coherent submillimeter, pulsed THz, and IR Fourier transform spectroscopy. The classical oscillator model and generalized four-parameter model were used to analyze the spectra obtained, and the parameters of the models were determined. We analyzed main absorption processes, which include contributions of both phonons and multi-phonon processes as well as electron transitions in Tb3+ ions and two antiferromagnetic resonance modes in the Fe subsystem. As a result, the spectra of real and imaginary parts of permeability and permittivity were obtained. A distinctive feature of the studied electrodynamic response in TbFeO3 is a significant absorption in the THz range due to multi-phonon processes, which exceeds optical phonon contribution by an order of magnitude at room temperature.

Automated summary

The absorption mechanisms in orthoferrite TbFeO3 were studied using various spectroscopy techniques. The spectra were analyzed using the oscillator model and four-parameter model, and the parameters were determined. The main absorption processes were identified, including contributions from phonons, multi-phonon processes, electron transitions, and antiferromagnetic resonance modes. The electrodynamic response in TbFeO3 showed significant absorption in the THz range due to multi-phonon processes, surpassing optical phonon contribution by an order of magnitude at room temperature.