Continuation of the Program on Photoinduced Magnetism

摘要

Photoinduced magnetism (PIM) studies were successfully extended to the class of organic-based high Tc magnetic semiconductors based on V(TCNE)2, with PIM discovered in the chemical vapor deposition (CVD) prepared films to nearly 150 K. A previously unknown phenomenon, photoinduced diamagnetism (reversible decrease in the magnetization) was revealed in these materials. We developed a powerful new experimental method to studies PIM, Photoinduced FerroMagnetic Resonance (PIFMR). PIFMR determined that the photoinduced decrease of the magnetization of V(TCNE)2 was due to a photoinduced reduction in the permeability of V(TCNE)2 and did not affect the saturation magnetization of the V(TCNE)2. Thus photomodulation of the permeability of antenna materials incorporating V(TCNE)2 may be possible. V(sub X)M(sub 1-x)(TCNE)2 z(CH2Cl2) samples, with M = Co, Fe were prepared in solution of CH2Cl2 to further control the permeability and PIM. Modification of the CVD reactor to prepare films with three components: V(CO)6, CO2(CO)s, and TCNE are being made. These modifications must accommodate the different vapor pressures and reactivity rates for the different components. When these modifications are complete this will be a powerful means to prepare films for future PIM development as well as for preparation of three component films for incorporation in multilayers for controlled permeability.