The high-pressure Electron Spin Resonance (ESR) measurements were preformed on TDAE-C60 single crystals and stability of the polymeric phase was established in the P−T parameter space. At 7 kbar the system undergoes a ferromagnetic to paramagnetic phase transition due to the pressure-induced polymerization. The polymeric phase remains stable after the pressure release. The depolymerization of the pressure-induced phase was observed at the temperature of 520 K. Below room temperature, the polymeric phase behaves as a simple Curie-type insulator with one unpaired electron spin per chemical formula. The TDAE+ donor-related unpaired electron spins, formerly ESR-silent, become active above the temperature of 320 K and the Curie-Weiss behavior is re-established.
@article{arxiv.cond-mat/0207034,
title = {The polymer phase of the TDAE-C$_{60}$ organic ferromagnet},
author = {Slaven Garaj and Takashi Kambe and László Forró and Andrzej Sienkiewicz and Motoyasu Fujiwara and Kokichi Oshima},
journal= {arXiv preprint arXiv:cond-mat/0207034},
year = {2009}
}