Anomalous thermal expansion of iron borate crystals FeBO_3 near the Neel point

摘要

Study of the anomalous behavior of the linear thermal expansion coefficient near the antiferromagnetic phase transitions in iron borate crystals FeBO_3 are reported. The lattice parameters and volume of FeBO_3 have been measured in the temperature range 25-300°C by the X-ray diffraction method. The thermal expansion is evidently sharply anisotropic and spike near the Neel temperature.