Luo Shirui, Tan Fang, Jiang Dapeng, Liu Honggang, Liu Tingyu, Wei Liening, Liu Yu, Zhang Zhen, Ma Fengkai, Zhang Zhonghan, Kou Huamin, Qin Huaize, Zhu Jingguo, Hu Junjie, Hong Wei, Su Liangbi
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai 201899 China.
Laser Fusion Research Center Mianyang Sichuan 621900 China.
RSC Adv. 2025 Jan 29;15(4):2890-2899. doi: 10.1039/d4ra08622h. eCollection 2025 Jan 23.
Employing electron paramagnetic resonance (EPR) and excitation and photoluminescence (PL) spectra, changes of the local structure of Gd ions were investigated for the CaF crystals containing 0.00015, 0.17, 1.22, 5.75 at% Gd ions, respectively. The obtained spin Hamiltonian parameters of the cubic configuration Gd monomer are = 1.9862, = -2.3153 ± 0.015 MHz and = -0.0005 ± 0.001 MHz. The peak-to-peak width of the EPR lines of the cubic configuration Gd is significantly broadened and partially quenched with the increase of the Gd concentration, which indicates that the exchange and dipole interactions between Gd-Gd are enhanced. From theoretical calculations, combined with experimentally measured angular dependence, we found that for the 1.22 at% Gd:CaF crystals, Gd remains essentially cubic, and the majority of the Gd ions are distributed as a dimer conformation along the [110] direction and at a distance of about 7.7 Å.
利用电子顺磁共振（EPR）以及激发和光致发光（PL）光谱，分别对含有0.00015、0.17、1.22、5.75原子百分比钆离子的CaF晶体中钆离子的局部结构变化进行了研究。所得到的立方构型钆单体的自旋哈密顿参数为 = 1.9862， = -2.3153 ± 0.015兆赫兹， = -0.0005 ± 0.001兆赫兹。随着钆浓度的增加，立方构型钆的EPR线的峰峰宽度显著变宽且部分淬灭，这表明钆-钆之间的交换和偶极相互作用增强。通过理论计算，并结合实验测量的角度依赖性，我们发现对于1.22原子百分比钆掺杂的CaF晶体，钆基本上保持立方构型，并且大多数钆离子沿[110]方向以二聚体构象分布，间距约为7.7埃。
