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论文类型：期刊论文

发表时间：2020-03-01

发表刊物：JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

收录刊物：EI、SCIE

卷号：497

ISSN号：0304-8853

关键字：Organic magnet; Room-temperature ferromagnetism; Tris(8-hydroxyquinoline)iron; Organic semiconductor; Density functional theory

摘要：Room-temperature ferromagnetism was obtained in an organic, originally paramagnetic tris(8-hydroxyquinoline)iron(Feq(3)) molecule by doping paramagnetic aluminum atoms. The Al-doped Feq(3) films were prepared on Si substrates by vacuum thermal co-evaporation. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed that all the doped Al atoms react with the O atoms of Feq(3) molecule. The magnetic measurement by a physical property measurement system indicated that the Al-doped Feq(3) film shows obvious ferromagnetic property even at room temperature. First-principles density functional theory (DFT) calculations were used to study the electronic structure and magnetic properties. DFT calculations results indicated that the doped Al atom tends to place at the attraction center with respect to the two O atoms of Feq(3) quinoline ligands, forming -O-Al-O- complex. Compared with pure Feq(3) cell, the energy differences between antiferromagnetic and ferromagnetic states became much larger after Al atoms doped into Feq(3) cell. This may explain the roomtemperature ferromagnetism observed in the prepared Al-doped Feq(3) film.