Al2O3:Fe3+体系晶格局域结构的EPR理论研究

本文通过分析Al2O3∶Fe3+体系中Fe3+离子的EPR谱,研究Fe3+的局域晶体结构结果表明Al2O3∶Fe3+的局域结构存在各向异性膨胀.用拟合EPR谱的低对称参量D和(a-F)实验值的方法,求得两个三棱锥的棱与C3轴的夹角分别为θ1=46.54°和θ2=61.26°,相对于原Al2O3结构的畸变角分别是Δθ1=-1.1°±0.1°,Δθ2=-1.8°.两畸变角同时均小于0说明Al2O3∶Fe3+体系中含Fe3+离子的晶格主要产生沿C3轴的伸长畸变.

EPR theoretical study of the local lattice structure in Al2O3:Fe3+ system

By analyzing EPR spectrum of Fe~(3+) ion in Al2O3∶Fe3+ system, the local crystal structure around impurity ion in the crystal has been studied. The result indicates that there exists an anisotropic expansion in the local crystal structure. By simulating the experimental data of the EPR parameters D and (a-F) in Al2O3∶Fe3+ system, the distortions of the angles in the two pyramids of Al_2O_3∶Fe~(3+) to be Δθ_1=-1.1°±(0.1°) and Δθ_2=-1.8° along the C_3 axis are determined, respectively. The two distorted angles are simultaneously less than zero means that there mainly exists an elongated distortion along C_3 axis for the Fe3+ ion in its doped sub-lattice.