Organic-based magnetic semiconductor thin film of Fe(TCNQ)x∼2 developed by physical vapor deposition and local spin density induced core-level shifts

• First development of organic-based magnetic semiconductor thin film of Fe(TCNQ)x.
• Demonstration of local spin density induced core-level shifts in TCNQ− anion.
• Characterization of charge transfer between Fe and TCNQ using FT-IR and XPS analysis.
• Demonstration of magnetic semiconductor properties of Fe(TCNQ)x.

Thin film of Fe(TCNQ:tetracyanoquinodimethane)x∼2 that exhibits both ferromagnetic and semiconducting behavior was developed by physical vapor deposition. The IR and photoemission spectra display clear evidences of coordination between metal and TCNQ based on charge transfer rather than physical mixture. The shifts of C and N 1s core-level spectra due to metal-TCNQ coordination reveal the local spin density of the TCNQ− anion, predicted by DFT calculation. The valence band spectra of the Fe(TCNQ)x∼2 thin film also confirm the formation of a singly occupied molecular orbital (SOMO) in TCNQ-, which leads to long-range magnetic order as confirmed by a vibrating sample magnetometer.