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The polymer phase of the TDAE-C$_{60}$ organic ferromagnet

Slaven Garaj·Takashi Kambe·László Forró·Andrzej Sienkiewicz·Motoyasu Fujiwara·Kokichi Oshima
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Abstract

The high-pressure Electron Spin Resonance (ESR) measurements were preformed on TDAE-C$_{60}$ 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.

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Slaven Garaj, Takashi Kambe, László Forró, Andrzej Sienkiewicz, Motoyasu Fujiwara, Kokichi Oshima. 2002-07-01. The polymer phase of the TDAE-C$_{60}$ organic ferromagnet. https://doi.org/10.1103/physrevb.68.144430

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