The electrical conductivity of epitaxial $\mathrm{BaTi}{\mathrm{O}}_3$ films was studied by small-signal impedance spectroscopy at temperatures of 10–720 K using Pt-$\mathrm{BaTi}{\mathrm{O}}_3-\mathrm{SrRu}{\mathrm{O}}_3$ capacitors. The $\sim 150$-nm-thick $\mathrm{BaTi}{\mathrm{O}}_3$ films possessed different lattice strains and degrees of oxygen deficiency. A crossover between the low-temperature hopping of small polarons and the high-temperature semiconductor- to metal-type behavior was demonstrated in all films. It was suggested that the small electron polarons originate from self-trapping at Ti in the stoichiometric tensile-strained film and from trapping at Ti next to the oxygen vacancy in the oxygen-deficient films. The conduction-band transport was ascribed to the thermally activated release of the trapped electrons. It was pointed out that the electronic release can mimic the motion of oxygen vacancies, which are actually immobile.

中文翻译：

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外延钛酸钡薄膜中的电荷传输

外延电导率 $\mathrm{钡钛}{\mathrm{Ø}}_3$ 在10–720 K的温度下，采用Pt-$\mathrm{钡钛}{\mathrm{Ø}}_3-锶{\mathrm{Ø}}_3$电容器。的$〜150$-nm厚 $\mathrm{钡钛}{\mathrm{Ø}}_3$薄膜具有不同的晶格应变和缺氧程度。在所有薄膜中都证明了小极化子的低温跳跃与高温的半导体-金属型行为之间的交叉。有人认为，小电子极化子是由化学计量的拉伸薄膜中的Ti处的自陷和缺乏氧的薄膜中的氧空位附近的Ti处的陷获引起的。导带传输归因于俘获电子的热活化释放。有人指出，电子释放可以模拟实际上不动的氧空位的运动。