Spin-wave resonances in bismuth orthoferrite at high temperatures

Abstract

Spin-wave resonances in pelletized powder of bismuth orthoferrite (BiFeO3) were studied in transmission spectroscopy at frequencies of 0.1-0.75 THz and in the temperature range of 300-650 K. A vector network analyzer with frequency extenders was used in conjunction with temperature scans. We extended the experimental coverage of spin-wave resonances in BiFeO3 up to almost the Néel temperature. We observed that Ψ1(1) and Ψ1(2) modes are degenerate around 420 K due to the temperature dependences of the magnetic anisotropy and the Dzyaloshinskii-Moriya interaction.