Magnetic properties and structures of iron phthalocyanine doped with potassium

The magnetic properties of iron phthalocyanine doped with potassium (K-FePc) were examined. K-FePc obtainedat 550 °C for 5hr is regarded as ferromagnetic based on the SQUID measurements. The saturation magnetization of this sample is 15.3emuG/g at 298K. The existence of isolated iron was not able to be confirmed in the sample by means of X-ray diffraction analysis and TEM observation. In the ESR spectra, the g-value of K-FePc was in contrast to that of isolated iron. These results suggest that the origin of the ferromagnetism of K-FePc is not due to isolated iron but other ferromagnetic interactions. The thermal history (cooling rate, post heat treatment) after the doping reaction significantly influences the magnetic property.