Lupi S, Baldassarre L, Mansart B, Perucchi A, Barinov A, Dudin P, Papalazarou E, Rodolakis F, Rueff J-P, Itié J-P, Ravy S, Nicoletti D, Postorino P, Hansmann P, Parragh N, Toschi A, Saha-Dasgupta T, Andersen O K, Sangiovanni G, Held K, Marsi M
CNR-IOM and Dipartimento di Fisica, Universitá di Roma 'La Sapienza', Piazzale A. Moro 2, I-00185 Roma, Italy.
Nat Commun. 2010 Nov 2;1:105. doi: 10.1038/ncomms1109.
V(2)O(3) is the prototype system for the Mott transition, one of the most fundamental phenomena of electronic correlation. Temperature, doping or pressure induce a metal-to-insulator transition (MIT) between a paramagnetic metal (PM) and a paramagnetic insulator. This or related MITs have a high technological potential, among others, for intelligent windows and field effect transistors. However the spatial scale on which such transitions develop is not known in spite of their importance for research and applications. Here we unveil for the first time the MIT in Cr-doped V(2)O(3) with submicron lateral resolution: with decreasing temperature, microscopic domains become metallic and coexist with an insulating background. This explains why the associated PM phase is actually a poor metal. The phase separation can be associated with a thermodynamic instability near the transition. This instability is reduced by pressure, that promotes a genuine Mott transition to an eventually homogeneous metallic state.
V(2)O(3)是莫特转变的原型系统，莫特转变是电子关联最基本的现象之一。温度、掺杂或压力会在顺磁金属（PM）和顺磁绝缘体之间引发金属-绝缘体转变（MIT）。这种或相关的MIT具有很高的技术潜力，尤其适用于智能窗户和场效应晶体管。然而，尽管这种转变对研究和应用很重要，但其发生的空间尺度尚不清楚。在这里，我们首次揭示了具有亚微米横向分辨率的Cr掺杂V(2)O(3)中的MIT：随着温度降低，微观区域变为金属性，并与绝缘背景共存。这解释了为什么相关的PM相实际上是一种不良金属。相分离可能与转变附近的热力学不稳定性有关。压力会降低这种不稳定性，促使真正的莫特转变最终形成均匀的金属态。
