Abstract
Results obtained from diffuse neutron scattering investigations and those derived from magnetic Bragg peaks on single crystals of the planar antiferromagnet KFeF4 in the critical region reveal that the temperature dependence of the two‐dimensional short range magnetic order and of the sublattice magnetization follow (TTN)−νv and (1 – T/TN)β laws, respectively, where v = 0.60, β = 0.20, and TN = 148 K. Mössbauer measurements at 300K showed that for KFeF4 the isomer shift is (+ 0.138 ± 0.002) mm/s see page 232. and the quadrupole splitting is (1.460 ± 0.005) mm/s see page 232. . In the temperature range 0.96 < T/TN < 0.998 the internal magnetic field follows the power law Hin(T) = H(0) D (1 – T/TN)β, where H(0) = H (4.2 K) = (540 ± 4) kOe, TN = (141.51 ± 0.05) K, D = 1.12 ± 0.03, and β = 0.209 ± 0.008.