Hydrogen donors and Ti3+ ions in reduced TiO2 crystals
Hydrogen donors and Ti3+ ions in reduced TiO2 crystals
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DOI：
10.1063/1.3630964
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发表时间：
2011-09-01
影响因子：
3.2
通讯作者：
Halliburton, L. E.
中科院分区：
文献类型：
--
作者：
Brant, A. T.;Yang, Shan;Halliburton, L. E.
采用电子顺磁共振（EPR）和电子-核双共振（ENDOR）技术对金红石型TiO 2晶体中的中性氢供体进行了鉴定和表征。这些光谱在5 K附近观察得最好。中性供体在没有光激发的情况下存在于在氮气气氛中在高温下略微还原的晶体中。氧化晶体在低温下也可以产生相同的缺陷。该晶格中的中性氢供体由邻近取代OH-分子离子的取代Ti 3+离子组成。OH-分子的轴位于基面中，氢离子在垂直于Ti-O键的方向上从氧中延伸出来。从EPR和ENDOR谱的角度依赖性获得自旋哈密顿参数（g矩阵的主值为1.9732、1.9765和1.9405，H-1超精细矩阵的主值为-0.401、+0.616和-0.338 MHz）。与+0.616 MHz主值相关联的主轴在基面中与[110]方向成22.9度，并且与-0.338 MHz主值相关联的主轴沿沿着[001]方向。我们的研究结果表明，间隙Ti 3+离子是不是占主导地位的浅施主轻微还原TiO 2（金红石）晶体。(C)2011年美国物理学会。[doi：10.1063/1.3630964]
Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify and characterize the neutral hydrogen donor in TiO2 crystals having the rutile structure. These spectra are best observed near 5 K. The neutral donors are present without photoexcitation in crystals that have been slightly reduced at high temperature in a nitrogen atmosphere. The same defects can be photoinduced at low temperature in oxidized crystals. The neutral hydrogen donor in this lattice consists of a substitutional Ti3+ ion adjacent to a substitutional OH- molecular ion. The axis of the OH- molecule lies in the basal plane with the hydrogen ion extending out from the oxygen in a direction perpendicular to the Ti-O bonds. Spin-Hamiltonian parameters are obtained from the angular dependence of the EPR and ENDOR spectra (principal values are 1.9732, 1.9765, and 1.9405 for the g matrix and -0.401, + 0.616, and -0.338 MHz for the H-1 hyperfine matrix). The principal axis associated with the + 0.616 MHz principal value is in the basal plane 22.9 degrees from a [110] direction and the principal axis associated with the -0.338 MHz principal value is along the [001] direction. Our results show that interstitial Ti3+ ions are not the dominant shallow donors in slightly reduced TiO2 (rutile) crystals. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3630964]