ABSTRACT
The electron paramagnetic resonance (EPR) parameters of the impurity Ni3+ (and Cu2+) in MgNH4PO4·6H2O (MAPH) are theoretically studied from the perturbation formulas for 3d7 (and 3d9) ions under orthorhombically compressed (and elongated) octahedra, respectively. In the above formulas, the related molecular orbital coefficients are quantitatively determined from the cluster approach in a uniform way. In the calculation model, the impurity Ni3+ and Cu2+ ions were ascribed to occupy the host octahedral Zn2+ site, the required crystal-field parameters are correlated with the local structures of the impurity Ni3+ and Cu2+ in MAPH. Based on calculation, the compressed [NiO6]9- cluster (and elongated [CuO6]10- cluster) are found to suffering the axial compression of 0.051 Å (and elongation of 0.125 Å) along z-axis, meanwhile, the planar bonds are found to experience the relative variations of 0.028 Å (and 0.05 Å), respectively, due to the Jahn–Teller effect. The theoretical EPR parameters based on the above lattice distortions agree well with the experimental data, and the local structures of the Ni3+ and Cu2+ in MAPH are discussed.
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Yadong Li
Yadong Li is graduate student in Nanchang Hangkong University, her research interests include the investigation on electron paramagnetic resonance (EPR) spectroscopy of transition metal ions in materials.
Huaming Zhang
Huaming Zhang is Professor in the Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, P.R. China. He got His PhD degree in University of Electronic Science and Technology of China, Chengdu. His research interests include the investigation on electron paramagnetic resonance (EPR) spectroscopy of transition metal ions in materials, preparation and performance control of electrocatalyst.
Di Gui
Di Gui is Lecturer in the Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, P.R. China. He got his PhD degree in Huazhong University of Science and Technology of China, Wuhan. His research interests include the investigation on mechanical and optical properties of metal inorganic-organic hybrid frameworks.
Jian-Zhuang Yin
Jian-Zhuang Yin is lecturer in the National Demonstration Center for Experimental College Physics Education, Nanchang Hangkong University, P.R. China. He got his PHD degree in Education from Sichuan University, Chengdu, P.R. China. His area of research interest is quantum transport.
W.B. Xiao
W. B. Xiao is a full Professor in the Key Laboratory of Nondestructive Testing, Ministry of Education, Nanchang Hangkong University, P.R. China. In 2008,he obtained his PhD degree in microelectronics and solid state electronics from the Institute of semiconductors, Chinese Academy of Sciences, China. His research interests concentrate on semiconductor physics and photoelectric detection.