Pressure-Dependent Reversible Increase in Tc for the Ferrimagnetic 2-D MnII(TCNE)I(OH2) and 3-D MnII(TCNE)3/2(I3)1/2·zTHF Organic-Based Magnets

The pressure dependence of the magnetic properties of ferrimagnetic MnII(TCNE)I(OH2) up to 14.05 kbar and MnII(TCNE)3/2(I3)1/2·zTHF up to 14.32 kbar were studied. For MnII(TCNE)I(OH2), two distinct pressure regions separated at ∼1 kbar were evident in both the temperature and the field-dependent magnetic measurements. No increase of the magnetic properties was observed in the low-pressure region, while significant increases to the magnetic ordering temperature, Tc, bifurcation temperature, Tb, coercive field, Hcr, and remnant magnetization, Mr, were evident in the high-pressure region. The Tc, Tb, Hcr, Mr, and M(5 T) reversibly increased from ambient pressure values of 169 K, 169 K, 690 Oe, 620 emuOe/mol, and 13 800 emuOe/mol to 257 K, 261 K, 1460 Oe, 2300 emuOe/mol, and 17 100 emuOe/mol at 14.05 kbar, respectively. For MnII(TCNE)3/2(I3)1/2·zTHF, the Tc and Tb were nearly coincident and increased linearly from 173 and 173 K, respectively, at ambient pressure to 273 and 272 K, respectively, at 14.32 kbar. ...