Photo‐EPR and magneto‐optical spectroscopy of iron centres in ZnO
Photo‐EPR and magneto‐optical spectroscopy of iron centres in ZnO
复制标题
ZnO 中铁中心的光电 EPR 和磁光光谱
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Bayer
中科院分区：
文献类型：
--
作者：
D. Azamat;J. Debus;D. Yakovlev;V. Ivanov;M. Godlewski;M. Fanciulli;M. Bayer
氧化锌作为一种很有前途的光电子学和自旋电子学材料，引起了人们越来越大的兴趣。通过掺杂过渡金属离子可以控制氧化锌的磁性，Fe3+是其中一个有趣的候选者。用光电子顺磁共振(EPR)和光谱学方法研究了水热和化学气相输运生长的氧化锌单晶中Fe3+中心的性质。对氧化锌中铁离子中心4T1(G) → 6A1(6S)的自旋禁忌电偶极跃迁的塞曼分量的详细磁光研究揭示了Γ8(4T1)最低激发态精细结构的三角对称性。在10 T的外加磁场和2~30 K的温度范围内，测量了8 T处塞曼分量的能量位置随外加磁场方向的变化。对塞曼谱线的角度变化进行了详细的检查，发现有两个磁性不等价的Fe3+中心。这些特殊特征由维度BJ3的更高等级塞曼项的贡献来解释。在水热法生长的氧化锌单晶中，除了存在三种电荷补偿的铁中心外，还在暗条件下检测到了三个三方铁中心的光生EPR谱。
ZnO has attracted increasing interest as promising material for optoelectronics and spintronics. Magnetic properties of ZnO can be controlled by doping with transition metal ions among which Fe3+ is one of the interesting candidates. We report on the properties of Fe3+ centres in hydrothermally and chemical vapour transport grown ZnO single crystals investigated by photo‐electron paramagnetic resonance (EPR) and optical spectroscopy. Detailed magneto‐optical studies of Zeeman components of spin‐forbidden electric dipole transitions 4T1(G) → 6A1(6S) of Fe3+ centre in ZnO reveal the trigonal symmetry of fine structure of lowest Γ8 (4T1) excited state. The studies were performed in external magnetic fields up to 10 T and in the temperature range from 2 to 30 K. The energy positions of the Zeeman components at 8 T were measured as a function of the direction of applied magnetic field in $(1ar {2}10)$ and (0001) planes. The detailed check of the angular variation of Zeeman lines shows two magnetically non‐equivalent Fe3+ centres. These special features were accounted by contribution of higher rank Zeeman terms of dimension BJ3. The photo‐generated EPR spectra of trigonal Fe3+ centres were detected in hydrothermally grown ZnO single crystals in addition to three types of charge compensated iron centres presented in these samples in the dark conditions.