Chemistry Letters, Vol.30, No.1, 32-33, 2001
Magnetic phase transition between ferromagnetic high-temperature phase and antiferromagnetic low-temperature phase in 5-carboxy-2-thienyl nitronyl nitroxide
From the measurements of the temperature dependence of magnetization, a magnetic phase transition at 145 K with a thermal hysteresis is found for an organic radical 5-carboxy-2-thienyl nitronyl nitroxide. Ferromagnetic intermolecular interaction is observed in the high-temperature phase while antiferromagnetic interaction is obtained for the low-temperature phase.