The α-CuPc films without and with light Ni-doping were characterized by X-ray photoelectron spectroscopy to confirm the absence of other ferromagnetic impurities.

The α-CuPc film exhibited ferromagnetic hysteresis with saturation magnetization of ∼6.77 emu/cm³ and coercivity of ∼96 Oe at 280 K, while that of the Ni-doped α-CuPc film are ∼0.69 emu/cm³ and ∼113 Oe, respectively.

Through the density functional theory calculations, the origin of the ferromagnetism arise from Cu 3d states and N 2s2p electronic spin polarization, as well as p–d exchange coupling interactions, and spin-unbalanced electronic structure of C 2p induced by the π–π interactions.