Experimental and theoretical study of the electronic structures of α-PbO and β-PbO2
Experimental and theoretical study of the electronic structures of α-PbO and β-PbO2
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DOI：
10.1039/b612323f
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发表时间：
2007-01-01
影响因子：
--
通讯作者：
Watson, Graeme W.
中科院分区：
文献类型：
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作者：
Payne, David J.;Egdell, Russell G.;Watson, Graeme W.
通过X射线光电子能谱、X射线吸收谱和X射线发射谱研究了α-PbO和β-PbO 2的电子结构，并在密度泛函理论的框架内进行了能带结构计算。发现在两种氧化物的价带底部的峰的相对强度之间的Al K α X-射线光电子能谱和O K壳层X-射线发射光谱的变化显着，表明与此相关的状态具有主导Pb 6s字符。这一发现与从能带结构计算得到的部分态密度雅阁，但与传统观点不同，传统观点认为PbO中的Pb 6s态接近费米能，并与空的6p态杂交，得到基于金属的定向6s - 6p孤对。β-PbO 2的光电发射开始包含一个定义明确的金属费米边缘。的发病结构的位置表明，PbO 2的金属性质所产生的主价带以上的导带状态的占领，可能产生的氧空位缺陷。的β-PbO 2的传导电子强烈扰动的Pb核心水平的电离，引起独特的卫星在核心XPS的能量对应于那些的传导电子等离子体。
The electronic structures of alpha-PbO and beta-PbO2 have been investigated by X-ray photoemission, X-ray absorption and X-ray emission spectroscopies, supported by bandstructure calculations performed within the framework of density functional theory. The relative intensity of a peak found at the bottom of the valence band for both oxides changes dramatically between Al K alpha X-ray photoemission and O K shell X-ray emission spectra, demonstrating that the states associated with this peak possess dominant Pb 6s character. This finding is in accord with partial densities of states derived from bandstructure calculations but is at variance with the conventional view that the Pb 6s states in PbO are close to the Fermi energy and hybridise with empty 6p states to give a metal based directional 6s - 6p lone pair. The photoemission onset of beta-PbO2 contains a well-defined metallic Fermi edge. The position of the onset structure suggests that the metallic nature of PbO2 arises from occupation of conduction band states above the main valence band, probably arising from oxygen vacancy defects. The conduction electrons of beta-PbO2 are strongly perturbed by ionisation of Pb core levels, giving rise to distinctive satellites in core XPS whose energies correspond to those of the conduction electron plasmon.