Magnetization under high-pressure in organic ferromagnet α-TDAE-C60

Abstract The magnetization measurements under pressure were performed on the fullerene-based ferromagnet, α -TDAE- C 60 . We found that the saturation magnetization below the ferromagnetic ordering temperature T c is rapidly suppressed with increasing pressure and disappeared above P c 2 = 0.1 – 0.2 GPa . This pressure is remarkably lower than the critical pressure of polymerization P c = 0.7 GPa . On the contrary, T c is almost pressure independent below P c 2 , but, above P c 2 , could not be entirely determined because of the strong suppression of the magnetization. In the paramagnetic region, the susceptibility under pressure indicates the total number of spins remains unchanged around P c 2 as well as P c . We discuss these results compared with the high-pressure ESR.