The investigation of the defect structures for Co2+ in ZnO microwires, thin films and bulks. (July 2017)

• Record Type: Journal Article
• Authors: Ding, Chang-Chun; Wu, Shao-Yi; Wu, Li-Na; Xu, Yong-Qiang; Zhang, Li-Juan
• Is Part Of: Journal of physics and chemistry of solids. Volume 106(2017)
• Page Start: 94
• Page End: 98
• Publication Date: 2017-07
• Subjects: Electron paramagnetic resonance (EPR) -- Defect structures -- Co2+ -- ZnO; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2017.03.005
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The defect structures for Co 2+ in ZnO microwires, thin films and bulks are theoretically investigated by analyzing the electron paramagnetic resonance (EPR) parameters (zero-field splitting D, g factors g// and g⊥ and hyperfine structure constants A// and A⊥ ) for trigonally distorted tetrahedral 3d 7 clusters in a consistent way. The impurities Co 2+ are found to suffer the displacements (≈0.046, 0.044 and 0.045 Å) away from the ligand triangles along the C3 axis in ZnO microwires, thin films and bulks, respectively, which considerably reduce the trigonal distortions of the Zn 2+ sites in the hosts. Apart from the contributions from the conventional crystal-field (CF) mechanism, those from the charge-transfer (CT) mechanism are important and should be included in the EPR analysis. The defect structures and spectral properties of the three ZnO:Co 2+ systems are discussed. Highlights: The defect structures for Co 2+ in ZnO microwires, thin films and bulks are theoretically investigated. Co 2+ suffer the trigonal distortions away from the ligand triangles along the C3 axis due to Jahn-Teller effect. The contributions of the charge-transfer (CT) mechanism are taken into account. The defect structures and spectral properties of the three ZnO:Co 2+ systems are discussed.