当前位置：
X-MOL 学术
›
Chem. Mater.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Dopants Promoting Ferroelectricity in Hafnia: Insights from a comprehensive Chemical Space Exploration
Chemistry of Materials ( IF 7.2 ) Pub Date : 2017-10-26 00:00:00 , DOI: 10.1021/acs.chemmater.7b02835 Rohit Batra 1 , Tran Doan Huan 1 , George A. Rossetti 1 , Rampi Ramprasad 1
Chemistry of Materials ( IF 7.2 ) Pub Date : 2017-10-26 00:00:00 , DOI: 10.1021/acs.chemmater.7b02835 Rohit Batra 1 , Tran Doan Huan 1 , George A. Rossetti 1 , Rampi Ramprasad 1
Affiliation
|
Although dopants have been extensively employed to promote ferroelectricity in hafnia films, their role in stabilizing the responsible ferroelectric nonequilibrium Pca21 phase is not well understood. In this work, using first-principles computations, we investigate the influence of nearly 40 dopants on the phase stability in bulk hafnia to identify dopants that can favor formation of the polar Pca21 phase. Although no dopant was found to stabilize this polar phase as the ground state, suggesting that dopants alone cannot induce ferroelectricity in hafnia, Ca, Sr, Ba, La, Y, and Gd were found to significantly lower the energy of the polar phase with respect to the equilibrium monoclinic phase. These results are consistent with the empirical measurements of large remnant polarization in hafnia films doped with these elements. Additionally, clear chemical trends of dopants with larger ionic radii and lower electronegativity favoring the polar Pca21 phase in hafnia were identified. For this polar phase, an additional bond between the dopant cation and the second nearest oxygen neighbor was identified as the root-cause of these trends. Further, trivalent dopants (Y, La, and Gd) were revealed to stabilize the polar Pca21 phase at lower strains when compared to divalent dopants (Sr and Ba). On the basis of these insights, we predict that the lanthanide series metals, the lower half of alkaline earth metals (Ca, Sr, and Ba) and Y as the most suitable dopants to promote ferroelectricity in hafnia.
中文翻译：
哈夫尼亚促进铁电的掺杂剂：全面化学空间探索的见解
尽管已经广泛地使用掺杂剂来促进氧化f膜中的铁电性，但人们对它们在稳定负责的铁电性非平衡Pca 2 1相中的作用还没有很好的了解。在这项工作中，使用第一性原理计算，我们研究了近40种掺杂剂对本体氧化ha的相稳定性的影响，以确定可以促进极性Pca 2 1形成的掺杂剂。阶段。尽管未发现任何掺杂剂可稳定该极性相为基态，这表明在哈夫尼亚中，单独的掺杂剂不能诱导铁电，但发现Ca，Sr，Ba，La，Y和Gd会显着降低极性相的能量。到平衡单斜相。这些结果与掺杂有这些元素的氧化镁膜中大的剩余极化的经验测量结果一致。此外，具有较大离子半径和较低电负性的掺杂剂的明显化学趋势有利于极性Pca 2 1确定了哈弗尼亚期。对于该极性相，掺杂剂阳离子和第二近的氧邻域之间的额外键被确定为这些趋势的根本原因。此外，与二价掺杂物（Sr和Ba）相比，三价掺杂物（Y，La和Gd）显示出在较低的应变下稳定了极性Pca 2 1相。根据这些见解，我们预测镧系金属，碱土金属的下半部分（Ca，Sr和Ba）和Y是最合适的掺杂剂，以促进氧化f中的铁电性。
更新日期：2017-10-27
中文翻译：
哈夫尼亚促进铁电的掺杂剂：全面化学空间探索的见解
尽管已经广泛地使用掺杂剂来促进氧化f膜中的铁电性，但人们对它们在稳定负责的铁电性非平衡Pca 2 1相中的作用还没有很好的了解。在这项工作中，使用第一性原理计算，我们研究了近40种掺杂剂对本体氧化ha的相稳定性的影响，以确定可以促进极性Pca 2 1形成的掺杂剂。阶段。尽管未发现任何掺杂剂可稳定该极性相为基态，这表明在哈夫尼亚中，单独的掺杂剂不能诱导铁电，但发现Ca，Sr，Ba，La，Y和Gd会显着降低极性相的能量。到平衡单斜相。这些结果与掺杂有这些元素的氧化镁膜中大的剩余极化的经验测量结果一致。此外，具有较大离子半径和较低电负性的掺杂剂的明显化学趋势有利于极性Pca 2 1确定了哈弗尼亚期。对于该极性相，掺杂剂阳离子和第二近的氧邻域之间的额外键被确定为这些趋势的根本原因。此外，与二价掺杂物（Sr和Ba）相比，三价掺杂物（Y，La和Gd）显示出在较低的应变下稳定了极性Pca 2 1相。根据这些见解，我们预测镧系金属，碱土金属的下半部分（Ca，Sr和Ba）和Y是最合适的掺杂剂，以促进氧化f中的铁电性。
京公网安备 11010802027423号