Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Stacking Fault Induced Symmetry Breaking in van der Waals Nanowires
ACS Nano ( IF 15.8 ) Pub Date : 2022-11-22 , DOI: 10.1021/acsnano.2c09172 Eli Sutter 1, 2 , Hannu-Pekka Komsa 3 , Alexander A Puretzky 4 , Raymond R Unocic 4 , Peter Sutter 5
ACS Nano ( IF 15.8 ) Pub Date : 2022-11-22 , DOI: 10.1021/acsnano.2c09172 Eli Sutter 1, 2 , Hannu-Pekka Komsa 3 , Alexander A Puretzky 4 , Raymond R Unocic 4 , Peter Sutter 5
Affiliation
|
While traditional ferroelectrics are based on polar crystals in bulk or thin film form, two-dimensional and layered materials can support mechanisms for symmetry breaking between centrosymmetric building blocks, e.g., by creating low-symmetry interfaces in van der Waals stacks. Here, we introduce an approach toward symmetry breaking in van der Waals crystals that relies on the spontaneous incorporation of stacking faults in a nonpolar bulk layer sequence. The concept is realized in nanowires consisting of Se-rich group IV monochalcogenide (GeSe1–xSx) alloys, obtained by vapor–liquid–solid growth. The single crystalline wires adopt a layered structure in which the nonpolar A-B bulk stacking along the nanowire axis is interrupted by single-layer stacking faults with local A-A′ stacking. Density functional theory explains this behavior by a reduced stacking fault formation energy in GeSe (or Se-rich GeSe1–xSx alloys). Computations demonstrate that, similar to monochalcogenide monolayers, the inserted A-layers should show a spontaneous electric polarization with a switching barrier consistent with a Curie temperature above room temperature. Second-harmonic generation signals are consistent with a variable density of stacking faults along the wires. Our results point to possible routes for designing ferroelectrics via the layer stacking in van der Waals crystals.
中文翻译：
范德瓦尔斯纳米线中的堆垛层错引起的对称性破缺
虽然传统的铁电体基于块状或薄膜形式的极性晶体，但二维和层状材料可以支持中心对称构建块之间的对称性破缺机制，例如，通过在范德瓦尔斯堆中创建低对称性界面。在这里，我们介绍了一种解决范德瓦尔斯晶体对称性破缺的方法，该方法依赖于非极性体层序列中堆垛层错的自发结合。该概念在由富硒 IV 族单硫族化物 (GeSe 1– x S x)合金，通过气-液-固生长获得。单晶线采用层状结构，其中沿纳米线轴的非极性AB体堆叠被具有局部AA'堆叠的单层堆垛层错中断。密度泛函理论通过 GeSe（或富硒 GeSe 1– x S x合金）。计算表明，与单硫族化物单层类似，插入的 A 层应显示自发电极化，并具有与高于室温的居里温度一致的转换势垒。二次谐波生成信号与沿导线的堆垛层错密度可变一致。我们的结果指出了通过范德瓦尔斯晶体中的层堆叠设计铁电体的可能途径。
更新日期：2022-11-22
中文翻译：
范德瓦尔斯纳米线中的堆垛层错引起的对称性破缺
虽然传统的铁电体基于块状或薄膜形式的极性晶体，但二维和层状材料可以支持中心对称构建块之间的对称性破缺机制，例如，通过在范德瓦尔斯堆中创建低对称性界面。在这里，我们介绍了一种解决范德瓦尔斯晶体对称性破缺的方法，该方法依赖于非极性体层序列中堆垛层错的自发结合。该概念在由富硒 IV 族单硫族化物 (GeSe 1– x S x)合金，通过气-液-固生长获得。单晶线采用层状结构，其中沿纳米线轴的非极性AB体堆叠被具有局部AA'堆叠的单层堆垛层错中断。密度泛函理论通过 GeSe（或富硒 GeSe 1– x S x合金）。计算表明，与单硫族化物单层类似，插入的 A 层应显示自发电极化，并具有与高于室温的居里温度一致的转换势垒。二次谐波生成信号与沿导线的堆垛层错密度可变一致。我们的结果指出了通过范德瓦尔斯晶体中的层堆叠设计铁电体的可能途径。
京公网安备 11010802027423号