Structural and transport properties of epitaxial niobium-doped BaTiO3 films
Structural and transport properties of epitaxial niobium-doped BaTiO3 films
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DOI：
10.1063/1.3025434
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发表时间：
2008-11
影响因子：
4
通讯作者：
Yang Shao;R. Hughes;A. Dabkowski;G. Radtke;W. Gong;J. Preston;G. Botton
中科院分区：
文献类型：
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作者：
Yang Shao;R. Hughes;A. Dabkowski;G. Radtke;W. Gong;J. Preston;G. Botton
BaTi 1 − xNbxO 3薄膜，跨越整个范围的x，已被沉积在MgAl 2 O 4衬底上。X射线衍射测量表明单相薄膜的所有值的x，相反，以前报道的铌溶解度的限制。薄膜对高温氧气暴露表现出极端的敏感性，这会破坏导电性并严重破坏结晶度。在最佳生长条件下，增加x引起在氧化态下的Ti 4+到Ti 3+的转变，伴随着在x=0.2附近的超导体-金属转变的增加的导电性。随温度变化的磁性测量显示自旋矩的异常上升，这一特征支持小单重双极化子模型。
BaTi1−xNbxO3 films, spanning the entire range of x, have been deposited on MgAl2O4 substrates. X-ray diffraction measurements indicate single phase films for all values of x, contrary to a previously reported niobium solubility limit. Films show extreme sensitivity to high temperature oxygen exposure, which destroys conductivity and severely disrupts crystallinity. Under optimum growth conditions increasing x gives rise to a Ti4+ to Ti3+ transformation in the oxidation state accompanied by increased conductivity with a semiconductor-metal transition near x=0.2. Temperature dependent magnetic measurements show an anomalous rise in the spin moment, a feature supportive of the small singlet bipolaron model.