Weak Antiferromagnet Iron Borate FeBO3. Classical Object for Magnetism and the State of the Art

The simple lattice and magnetic structure, the high Néel temperature, the narrow antiferromagnetic resonance line of FeBO3, and the narrow electron paramagnetic resonance line of its isostructural diamagnetic analogs MBO3:Fe3+ (M = Ga, In, Sc, Lu) make iron borate unique for investigations and applications. Iron borate is a model crystal for numerous experimental and theoretical studies, including spin crossovers and metallization at megabar pressures and many-electron effects in optics and X-ray spectroscopy. The recent works dealing with the investigation of the properties of FeBO3 are reviewed.