Pressure and temperature dependences of the canting angle and increase in the magnetic ordering temperature, (), for the weak ferromagnet Li[TCNE]˙ (TCNE = tetracyanoethylene).

The hydrostatic pressure dependence of the magnetic ordering temperature, (), for the interpenetrating, diamondoid lattice-structured, weak ferromagnet (= canted antiferromagnet) Li[TCNE]˙ (TCNE = tetracyanoethylene) reversibly increases from 20.9 to 23.4 K at 9.73 kbar, an increase of 12% with a rate of increase, d/d, of 0.27 K kbar. The 5 T magnetization increased by 672% from 186 emu Oe mol at ambient pressure to an average of 1440 emuOe mol upon application of pressure. The remanent magnetization initially increases 30% from 10.8 to 14.0 emuOe mol from ambient to 0.06 kbar, and increases further by 6% to a maximum of 14.8 emuOe mol at 0.56 kbar before declining by 22% to 11.5 emuOe mol at 9.73 kbar. The pressure-dependent coercive field, (), initially decreases by 42% from 31.1 Oe at ambient pressure to 18 Oe at 0.06 kbar, then increases to 52 Oe at 9.73 kbar. The canting angle, , increases by 28% from 0.52° to 0.66° at 0.06 kbar, then decreases by 23% to 0.51° at 9.73 kbar, as well as increases by 2% from 0.536° to 0.548° from 1.8 to 2.5 K, before decreasing by 79% to 0.117° at 19 K. The interlattice interactions are attributed to be the primary exchange mechanism. Thus, () and () have similar dependencies that are attributed to a competition between an increase and a decrease in the intra- and interlayer C⋯N interlattice separations as the temperature and pressure increases.