title: Structural and Magnetic Properties of Transition-Metal-Doped Zn 1-x Fe x O.
abstract: The ability to produce high-quality single-phase diluted magnetic semiconductors (DMS) is the driving factor to study DMS for spintronics applications. Fe-doped ZnO was synthesized by using a low-temperature co-precipitation technique producing Zn 1-x Fe x O nanoparticles (x= 0, 0.02, 0.04, 0.06, 0.08, and 0.1). Structural, Raman, density functional calculations, and magnetic studies have been carried out in studying the electronic structure and magnetic properties of Fe-doped ZnO. The results show that Fe atoms are substituted by Zn ions successfully. Due to the small ionic radius of Fe ions compared to that of a Zn ions, the crystal size decreases with an increasing dopant concentration. First-principle calculations indicate that the charge state of iron is Fe (2+) and Fe (3+) with a zinc vacancy or an interstitial oxygen anion, respectively. The calculations predict that the exchange interaction between transition metal ions can switch from the antiferromagnetic coupling into its quasi-degenerate ferromagnetic coupling by external perturbations. This is further supported and explains the observed ferromagnetic bahaviour at magnetic measurements. Magnetic measurements reveal that decreasing particle size increases the ferromagnetism volume fraction. Furthermore, introducing Fe into ZnO induces a strong magnetic moment without any distortion in the geometrical symmetry; it also reveals the ferromagnetic coupling.
authors.affiliation: Faculty of Science, Physics Department, Fayoum University, Fayoum, 63514, Egypt.
authors.forename: T A
authors.initials: TA
authors.lastname: Abdel-Baset
authors.affiliation: Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai, 200241, China.
authors.forename: Yue-Wen
authors.initials: YW
authors.lastname: Fang
authors.affiliation: Spectroscopy Department, Physics Division, National Research Center, Giza, 12622, Egypt.
authors.forename: B
authors.initials: B
authors.lastname: Anis
authors.affiliation: Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai, 200241, China.
authors.forename: Chun-Gang
authors.initials: CG
authors.lastname: Duan
authors.affiliation: Faculty of Science, Physics Department, Fayoum University, Fayoum, 63514, Egypt. m.mohamed@hpstar.ac.cn.|Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, China. m.mohamed@hpstar.ac.cn.|Institute of Physics, Goethe University Frankfurt, Frankfurt/M, 60438, Germany. m.mohamed@hpstar.ac.cn.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Abdel-Hafiez
keywords: Ferromagnetism; Magnetic semiconductors; Zinc oxide