Interconfigurational and intraconfigurational transitions of Yb2+ and Yb3+ ions in hydroxyapatite: A cathodoluminescence study
Interconfigurational and intraconfigurational transitions of Yb2+ and Yb3+ ions in hydroxyapatite: A cathodoluminescence study
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DOI：
10.1016/j.actamat.2017.06.003
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发表时间：
2017-08
期刊：
影响因子：
9.4
通讯作者：
Luz A. Zavala;P. Fernández;E. Novitskaya;Jorge N. Díaz;M. Herrera;O. Graeve
中科院分区：
文献类型：
--
作者：
Luz A. Zavala;P. Fernández;E. Novitskaya;Jorge N. Díaz;M. Herrera;O. Graeve
利用阴极发光法研究了羟基磷灰石（HAp）粉末中Yb 2+离子的组态间跃迁和Yb 3+离子的组态内跃迁。我们的结果表明，由于4f135 d1轨道的分裂，HAp晶格中存在的强电场在镱离子的电子构型中诱导了多个能级。Yb 2+的化学发光光谱在3.27、2.98、2.85、2.53、2.27、2.09和1.63 eV处出现一系列尖峰，对应于Yb 2 + 4f135d1组态正八面体晶场三角畸变产生的多能级跃迁。Yb~（3+）的化学发光光谱显示出中心位于1.17，1.21，1.24和1.27eV的四个发射峰，它们是由Yb~（3+）的2F~（5/2）和2F~（7/2）态之间的组态跃迁产生的。两种类型的样品在不同的pH值下合成，导致镱离子的化合价的变化，这样的Yb 2 +/Yb 3+的比例为0.31和0.55，分别在pH值为6和4，合成的煅烧粉末，由X射线光电子能谱测定。两种样品的红外化学发光图像显示了粉末中Yb 3+掺杂剂的不均匀空间分布。在873 K的氧气气氛中，热处理的样品，导致猝灭的Yb 2+的发光由于氧化的Yb 2+到Yb 3+。
We present a cathodoluminescence (CL) study of the interconfigurational transitions of Yb2+and intraconfigurational transitions of Yb3+dopant ions in hydroxyapatite (HAp) powders. Our results demonstrate that strong electric fields present in the HAp lattice induce manifold levels in the electronic configuration of the ytterbium ions, due to splitting of the 4f135d1orbitals. CL spectra of Yb2+display a series of sharp peaks centered at 3.27, 2.98, 2.85, 2.53, 2.27, 2.09 and 1.63 eV, corresponding to transitions between multiple levels produced by a trigonal distortion of the regular octahedral crystal field of the Yb2+4f135d1configuration. CL spectra of Yb3+display four emissions centered at 1.17, 1.21, 1.24 and 1.27 eV, generated by intraconfigurational transitions between the2F5/2and2F7/2states of Yb3+ions. Two types of samples were synthesized at different pH values, resulting in variations of the valence of the ytterbium ions, such that the ratios of Yb2+/Yb3+were 0.31 and 0.55 in calcined powders synthesized at pH values of 6 and 4, respectively, as determined from X-ray photoelectron spectroscopy. Infrared CL images of the two samples show an inhomogeneous spatial distribution of the Yb3+dopant in the powders. Thermal treatment of the samples, at 873 K in an oxygen atmosphere, result in quenching of the Yb2+luminescence due to oxidation of the Yb2+into Yb3+.