We review the pyroelectric properties and electronic structure of Li2B4O7(110) and Li2B4O7(100) surfaces. There is evidence for a pyroelectric current along the [110] direction of stoichiometric Li2B4O7 so that the pyroelectric coefficient is nonzero but roughly 103 smaller than along the [001] direction of spontaneous polarization. Abrupt decreases in the pyroelectric coefficient along the [110] direction can be correlated with anomalies in the elastic stiffness contributing to the concept that the pyroelectric coefficient is not simply a vector but has qualities of a tensor, as expected. The time dependent surface photovoltaic charging suggests that surface charging is dependent on crystal orientation and doping, as well as temperature.
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机译:我们审查了Li2B4O7(110)和Li2B4O7(100)表面的热电性质和电子结构。有证据表明,沿化学计量的Li2B4O7的[110]方向存在热电流,因此热电系数为非零,但比沿自发极化的[001]方向小约10 3 sup>。沿[110]方向的热电系数突然下降可能与弹性刚度异常有关。 C mi> 33 mn> D mi> msubsup> mrow> mrow> math>促进了热电系数不仅是矢量而且具有张量性质的概念,这与预期的一样。与时间有关的表面光伏充电表明,表面充电取决于晶体的取向和掺杂以及温度。
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