Applied Surface Science, Vol.356, 1070-1076, 2015
Near room temperature ferromagnetism of copper phthalocyanine thin films
We reported near room temperature ferromagnetism of alpha-CuPc films without and with light Ni-doping. Two samples were characterized by X-ray photoelectron spectroscopy (XPS) to confirm the absence of other ferromagnetic impurities. The a-CuPc film exhibited ferromagnetic hysteresis with saturation magnetization of similar to 6.77 emu/cm(3) and coercivity of similar to 96 Oe at 280 K, while that of the Ni-doped alpha-CuPc film are similar to 0.69 emu/cm(3) and similar to 113 Oe, respectively. Through the density functional theory (DFT) 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 pi-pi interactions. (C) 2015 Elsevier B.V. All rights reserved.