Magnetic response of Mn(III)F(salen) at low temperatures

Abstract

The low temperature magnetic response of Mn(III)F(salen), salen = H 14C16N2O2, an S = 2 linear-chain system, has been studied. Using a single crystal with the field applied perpendicular to the chain direction, torque magnetometry, down to 20 mK and up to 18 T, revealed a feature at 3.8 T when T ≤ 400 mK. ESR (≈ 200 GHz) studies, using single crystals at 4 K and in 5 T, have not detected any signal. In 10 mT, the temperature dependence of the susceptibility of powder-like samples can be reasonably fit when J=kB = 50 K and g = 2. In addition, these data are unchanged for P ≤ 1:0 GPa. Using a randomly-oriented, powder-like, deuterated (12 of 14 H replaced by D) sample of 2.2 g at 270 mK, neutron scattering data, acquired with the Cold Neutron Chopper Spectrometer at the Spallation Neutron Source, show several well defined excitations that may be from the zero- eld energy levels of antiferromagnetic S = 2 spins with g = 2, J=kB = 50 K, D=kB = 2:8 K, and E=kB = 0:5 K.