Germanium telluride (GeTe) is both polar and metallic, an unusual combination of properties in any material system. The large concentration of free-carriers in GeTe precludes the coupling of external electric field with internal polarization, rendering it ineffective for conventional ferroelectric applications and polarization switching. Here we investigate alternate ways of coupling the polar domains in GeTe to external electrical stimuli through optical second harmonic generation polarimetry and in situ TEM electrical testing on single-crystalline GeTe nanowires. We show that anti-phase boundaries, created from current pulses (heat shocks), invert the polarization of selective domains resulting in reorganization of certain 71o domain boundaries into 109o boundaries. These boundaries subsequently interact and evolve with the partial dislocations, which migrate from domain to domain with the carrier-wind force (electrical current). This work suggests that current pulses and carrier-wind force could be external stimuli for domain engineering in ferroelectrics with significant current leakage.
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机译：碲化锗（GeTe）既是极性的又是金属的，是任何材料系统中特性的不寻常结合。 GeTe中大量的自由载流子排除了外部电场与内部极化的耦合，从而使其对常规铁电应用和极化切换无效。在这里，我们研究了通过光学二次谐波生成旋光法和单晶GeTe纳米线上的原位TEM电学测试，将GeTe中的极性域耦合到外部电刺激的替代方法。我们表明，由电流脉冲（热冲击）产生的反相边界反转了选择性域的极化，从而导致将某些71 o 域边界重新组织为109 o 边界。这些边界随后与部分位错相互作用并演化，部分位错通过载流子风（电流）在一个域和另一个域之间迁移。这项工作表明电流脉冲和载流子力可能是铁电体中具有大量电流泄漏的领域工程的外部刺激。
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