Hyperfine interactions in the intramolecular antiferromagnet (Fe salen C1)2

Abstract
Magnetic hyperfine interactions in (Fe salen C1)2 have been studied using the Mössbauer effect in external magnetic fields up to 80 kOe and for 4.2 ≤ T ≤ 80 °K. The low‐temperature results are adequately described by a simple intramolecular exchange model with J = 7.0 cm−1 and a hyperfine interaction constant of −180 kOe per unit spin. At higher temperature the effective field approximation breaks down. Data for (Fe salen)2O are also briefly reported.