Critical-Point Behavior of FeBO3 Single Crystals by Mössbauer Effect

Abstract

Mössbauer effect (ME) measurements of the hyperfine (hf) interaction in single crystals of FeBO₃, have been used to study the behavior of the sublattice magnetization near the Néel temperature. The ME spectra show that the two nearly antiferromagnetic sublattice moments lie within the easy plane, in agreement with symmetry considerations for weak ferromagnets with calcite structure. From about 0.94≤T/T_N≤0.9996 the hf field fits the equation H(T)=H₀D(1‐T/T_N)^β with β=0.354±0.005, D=1.208±0.001 and T_N=348.35°K to ±0.01°K precision and to ±0.2°K absolute accuracy.