High Resolution THz Optical Absorption Study of Antiferromagnetic Magnons in Hematite (alpha-Fe2O3)
Shin G. Chou, David F. Plusquellic, Paul E. Stutzman, Shuangzhen S. Wang, Edward J. Garboczi
We report the high resolution optical measurement for the temperature dependence of the antiferromagnetic resonance (AFMR) transition in alpha-Fe2O3 between (0.5 and 10)cm-1. We found that below the Morin transition temperature when the spins are perfectly antiparallel, the AFMR transition could be clearly observed. The absorption peak position over a large temperature range are found to be in good agreement with theoretical analysis. The high spectral resolution optical measurements as demonstrated in this study allows unprecedented zero-field analysis of the AFMR excitation in a previously challenging spectral region, suggesting the frequency-resolved measurement platform could be extended for non-destructive examination applications for antiferromagnetic materials and devices.