Magnetic measurements on molecule-based magnets under high pressure

The effects of pressure on two prototypes of molecule-based magnets have been investigated through dc magnetic measurements in an attempt to realize these higher transition temperatures (T-C's). The target compounds are (1) a genuine organic radical weak-ferromagnet, p-NC-C6F4-CNSSN (T-C = 35.5 K) with through-space intermolecular interaction and (2) a metal-complex ferrimagnet [Mn(en)](3)[Cr(CN)(6)](2)center dot 4H(2)O (T-C = 69 K) with a cyanide bridge network between magnetic metal ions. In (1), T-C is enhanced as dT(C)/dP = 22.0 K/GPa, and it exceeds 70 K at around 1.5 GPa. Exceeding a border of 70 K is worthy in the field of the genuine organic system. In (2), pressure dependences of T-C and magnetic moment have been investigated over wider pressure region. The ideal material control for higher-T-C was realized at around 5 GPa. Two types of pressure cells developed for these studies are also mentioned.