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arXiv 2101.04409cond-mat.str-elcond-mat.mtrl-sci
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通过应变工程在V2O3化合物中诱导室温Mott金属-绝缘体转变

Room temperature Mott metal-insulator transition in V2O3 compounds induced via strain-engineering

P. Homm, M. Menghini, J. W. Seo, S. Peters, J. -P. Locquet

AI总结:

本文通过异质外延应变工程在纯V2O3和1.5% Cr掺杂V2O3薄膜中实现了室温Mott金属-绝缘体转变,获得了高达100,000%的电阻率变化和宽范围光学常数,并提出了以面内晶格常数为可调参数的新相图,为下一代Mott器件开辟了新途径。

摘要:

三氧化二钒(V2O3)是一种典型的Mott绝缘体,其原子位置和电子关联会随着温度、压力或掺杂的变化而改变,从而产生不同的结构、磁性或电子相变。值得注意的是,在Cr掺杂V2O3块材中观察到的顺磁金属相与绝缘相之间的等结构Mott转变,迄今为止在薄膜化合物中一直难以实现。本文通过异质外延诱导的连续晶格形变,在1.5% Cr掺杂和纯V2O3薄膜中展示了室温Mott金属-绝缘体转变。借助可控的外延应变,不仅薄膜的结构,而且其本征电子和光学性质都被稳定在金属相与绝缘相之间的不同中间态,这些中间态在块材中是无法实现的。这使薄膜具有独特的特性,例如室温电阻率的巨大变化(ΔR/R高达100,000%)以及由应变调制的带隙所导致的宽范围光学常数值。我们为纯V2O3和Cr掺杂V2O3薄膜提出了一个新的相图,其中以工程化的面内晶格常数作为可调参数。我们的结果表明,通过外延应变控制关联体系中的相变,为创造下一代Mott器件提供了一种全新的激进方法。

英文摘要:

Vanadium sesquioxide (V2O3) is an archetypal Mott insulator in which the atomic positions and electron correlations change as temperature, pressure or doping are varied giving rise to different structural, magnetic or electronic phase transitions. Remarkably, the isostructural Mott transition in Cr-doped V2O3 between paramagnetic metallic and insulating phase observed in bulk has been elusive in thin film compounds so far. Here, via continuous lattice deformations induced by heteroepitaxy we demonstrate a room temperature Mott metal-insulator transition in 1.5% Cr-doped and pure V2O3 thin films. By means of a controlled epitaxial strain, not only the structure but also the intrinsic electronic and optical properties of the thin films are stabilized at different intermediate states between the metallic and insulating phases, inaccessible in bulk materials. This leads to films with unique features such as a colossal change in room temperature resistivity (DR/R up to 100,000 %) and a broad range of optical constant values, as consequence of a strain-modulated bandgap. We propose a new phase diagram for pure and Cr-doped V2O3 thin films with the engineered in-plane lattice constant as a tuneable parameter. Our results demonstrate that controlling phase transitions in correlated systems by epitaxial strain offers a radical new approach to create the next generation of Mott devices.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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