Using first principles calculations we show that several alkali lead halides potentially present collective ferroelectric polarization. This should occur at least at the nanoscale; it could be detected macroscopically provided it is not concealed by lattice vibrations in the temperature range of stability of the cubic perovskite phase. For potassium lead halides and for alkali lead fluorides, remarkably, the ferroelectric behavior turns hyperferroelectric, suggesting a more robust ferroelectric polarization in spite of depolarization potentials induced by charge accumulation on surfaces or interfaces.

中文翻译：

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从碱式卤化钙钛矿中的潜在铁电到超铁电

使用第一性原理计算，我们表明几种碱式卤化铅可能会出现集体铁电极化。这至少应该发生在纳米级。只要它在立方钙钛矿相稳定温度范围内未被晶格振动掩盖，就可以用肉眼观察到。对于卤化钾铅和碱金属氟化铅而言，显着地，铁电行为变成了高铁电性，尽管存在由于表面或界面上电荷积累引起的去极化电势，但仍显示出更强健的铁电极化。