The influence of magnetic field on the crystallization process has been examined in Cs2TCNQ3 (TCNQ=tetracyanoquinodimethane), a strongly Coulomb-correlated organic semiconductor. The crystal structure is unaffected by the magnetic field, while the electric, magnetic and optical properties change markedly if the magnetic field higher than a threshold (~4T) is applied during the crystal growth. The high-field crystals exhibit a very weak but distinct spontaneous magnetization with the exceedingly high Curie temperature of ~420K. The infrared and visible spectroscopy data show that this novel ferromagnetism concurs with the renormalization of the π* state of TCNQ radical anions, TCNQ-.
- Infrared and visible spectroscopy
- Magnetic field-induced acceptors
- Organic ferromagnetism
- TCNQ salt