Li self-diffusion in lithium niobate single crystals at low temperatures.
Li self-diffusion in lithium niobate single crystals at low temperatures.
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DOI：
10.1039/c2cp23548j
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
J. Rahn;E. Hüger;L. Dörrer;B. Ruprecht;P. Heitjans;H. Schmidt
中科院分区：
文献类型：
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作者：
J. Rahn;E. Hüger;L. Dörrer;B. Ruprecht;P. Heitjans;H. Schmidt
用二次离子质谱法研究了Li(2) o缺陷LiNbO(3)单晶在423 ~ 773 K（150 ~ 500℃）范围内Li(2) o的自扩散。利用离子束溅射富集(6)的薄层LiNbO(3)作为示踪源，可以研究纯同位素间扩散。扩散系数可以用Arrhenius定律描述，激活焓为（1.33±0.03）eV，这与文献中通过从头计算确定的单个Li空位的迁移能是一致的。在同一类型样品上的阻抗谱测量得出的电荷扩散率在误差范围内与示踪剂扩散率相同。在低温扩散行为中没有发现缺陷复合物形成的迹象。
Li self-diffusion in Li(2)O-deficient LiNbO(3) single crystals is investigated in the temperature range between 423 and 773 K (150-500 °C) by secondary ion mass spectrometry. A thin layer of ion-beam sputtered isotope enriched (6)LiNbO(3) was used as a tracer source, which allows one to study pure isotope interdiffusion. The diffusivities can be described by the Arrhenius law with an activation enthalpy of (1.33 ± 0.03) eV, which is in acceptable agreement with the migration energy of a single Li vacancy as determined by ab initio calculations given in the literature. Charge diffusivities as derived from impedance spectroscopy measurements on the same type of samples are identical to the tracer diffusivities within error limits. No indication of the formation of defect-complexes at low temperatures could be found in the diffusion behaviour.