Single‐crystal LiNbO3 surfaces processed in low‐temperature hydrogen plasma: XPS, REELS and AFM study
Single‐crystal LiNbO3 surfaces processed in low‐temperature hydrogen plasma: XPS, REELS and AFM study
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低温氢等离子体处理的单晶 LiNbO3 表面：XPS、REELS 和 AFM 研究
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
I. Drbohlav
中科院分区：
文献类型：
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作者：
H. Turčičova;J. Zemek;J. Toth;I. Drbohlav
铌酸锂单晶是广泛应用于光电子、全息、表面声波器件等领域的材料，在低温等离子体中进行了氢射频放电处理。目的是研究一种新的LiNbO3表面改性方法。利用XPS、反射电子能量损失谱（REELS）和原子力显微镜（AFM）对表面改性进行了研究。通过铌三维谱线的XPS研究揭示了等离子体效应：铌酸盐结构的分解和铌氧化物的出现。随后在4 keV电子能量下进行的REELS研究显示相关跃迁的特征电子损失能转移。氧和锂从表面逸出，氢从等离子体中吸收，产生氢化铌。铌酸盐单体电池的劣化伴随着传导电子的增强。随后的医用氧热再氧化并没有恢复原始的铌酸盐结构。再氧化后的表面形貌特征是细长的100 nm晶粒位于表面的正常位置。这种新顶层的主要成分是铌氧化物Nb2O5和NbO。目前的结果构成了铌酸锂等离子体改性复杂研究的一部分。等离子体处理引起的晶格缺陷类似于离子注入或金属离子掺杂：表面层的电学和光学性质与本体的电学和光学性质截然不同。版权所有©2002约翰威利父子有限公司
Single crystals of lithium niobate, which is a widely used material in opto‐electronics, holography, surface acoustic wave devices, etc., have been processed in a low‐temperature plasma of radiofrequency discharge in hydrogen. The aim was to examine a new kind of surface modification of LiNbO3. The surface modification has been studied by XPS, reflection electron energy‐loss spectroscopy (REELS) and atomic force microscopy (AFM). The XPS study via the Nb 3d spectral lineshape revealed the plasma effect: a decomposition of the niobate structure and the appearance of niobium oxides. The subsequent REELS study performed at 4 keV electron energy showed a transfer of characteristic electron‐loss energies of relevant transitions. Oxygen and lithium escape from the surface and hydrogen is incorporated from the plasma, producing niobium hydride. The deterioration of the niobate unit cells is accompanied by an enhancement of conduction electrons. The subsequent thermal reoxidation in medical oxygen did not restore the original niobate structure. The surface morphology after the reoxidation is characterized by elongated 100 nm grains situated normally to the surface. The main constituents of this new top layers are niobium oxides Nb2O5 and NbO. The present results form part of a complex study of the plasma modification of lithium niobate. The plasma processing induces lattice defects that are similar to those of ion implantation or metal ion doping: the electrical and optical properties of the surface layer drastically differ from those of the bulk. Copyright © 2002 John Wiley & Sons, Ltd.