Prediction of two-dimensional electron gas mediated magnetoelectric coupling at ferroelectric PbTiO 3 / SrTiO 3 heterostructures

作者：Lanying Wei, Chao Lian, Sheng Meng · 发表于：Physical review. B./Physical review. B · 年份：2017 · DOI：10.1103/physrevb.95.184102 · 被引用次数：24 · 研究领域：Ferroelectric and Piezoelectric Materials、Multiferroics and related materials、Electronic and Structural Properties of Oxides

First-principles calculations predict the emergence of magnetoelectric coupling mediated by two-dimensional electron gas (2DEG) at the ferroelectric ${\mathrm{PbTiO}}_{3}/{\mathrm{SrTiO}}_{3}$ heterostructure. Free electrons endowed by naturally existing oxygen vacancies in ${\mathrm{SrTiO}}_{3}$ are driven to the heterostructure interface under the polarizing field of ferroelectric ${\mathrm{PbTiO}}_{3}$ to form a 2DEG. The electrons are captured by interfacial Ti atoms, which surprisingly exhibits ferromagnetism even at room temperature with a small critical density of $\ensuremath{\sim}15.5\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}\mathrm{C}/{\mathrm{cm}}^{2}$. The ferroelectricity-controlled ferromagnetism mediated by interfacial 2DEG shows strong magnetoelectric coupling strength, enabling convenient control of magnetism by electric field and vice versa. The ${\mathrm{PbTiO}}_{3}/{\mathrm{SrTiO}}_{3}$ heterostructure is cheap, easily grown, and controllable, promising future applications in low-cost spintronics and information storage at ambient condition.