Surface-Tailored, Purely Electronic, Mott Metal-to-Insulator Transition
Mott transitions, which are metal-insulator transitions (MITs) driven by electron-electron interactions, are usually accompanied in bulk by structural phase transitions. In the layered perovskite Ca₁.₉Sr₀.₁RuO₄, such a first-order Mott MIT occurs in the bulk at a temperature of 154 kelvin on cooling...
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Published in | Science (American Association for the Advancement of Science) Vol. 318; no. 5850; pp. 615 - 619 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington, DC
American Association for the Advancement of Science
26.10.2007
The American Association for the Advancement of Science |
Subjects | |
Online Access | Get full text |
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Summary: | Mott transitions, which are metal-insulator transitions (MITs) driven by electron-electron interactions, are usually accompanied in bulk by structural phase transitions. In the layered perovskite Ca₁.₉Sr₀.₁RuO₄, such a first-order Mott MIT occurs in the bulk at a temperature of 154 kelvin on cooling. In contrast, at the surface, an unusual inherent Mott MIT is observed at 130 kelvin, also on cooling but without a simultaneous lattice distortion. The broken translational symmetry at the surface causes a compressional stress that results in a 150% increase in the buckling of the Ca/Sr-O surface plane as compared to the bulk. The Ca/Sr ions are pulled toward the bulk, which stabilizes a phase more amenable to a Mott insulator ground state than does the bulk structure and also energetically prohibits the structural transition that accompanies the bulk MIT. |
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Bibliography: | http://www.scienceonline.org/ ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 DE-AC05-00OR22725 USDOE Office of Science (SC) |
ISSN: | 0036-8075 1095-9203 |
DOI: | 10.1126/science.1145374 |