Modeling charge-imbalancedNaNbO3/SrTiO3superlattices: Lattice relaxation and metallicity

Abstract

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High mobility of the strongly confined hole gas in AgTaO3/SrTiO3

“…Both are not the case for the closely related (KO) À /(TiO 2 ) 0 and (NaO) À /(TiO 2 ) 0 p-type IFs, where the A site cations K and Na do not contribute to the metallic IF states. 10,11 In addition, at the M point the O p x ; p y orbitals dominate. As discussed before, the O 2p hole density in the TiO 2 IF layer is much higher than the Ag 4d and O 2p hole densities in the AgO IF layer.…”

“…8 Experiments have revealed a band gap for the (NaO) À /(TiO 2 ) 0 p-type IF in NaNbO 3 /STO, 9 whereas it has been found theoretically that metallicity can be induced in this system, depending on the IF configuration and the layer ratio. 10 The p-type IFs in KTaO 3 /STO, NaTaO 3 / STO, and LaGaO 3 /STO show a metallic behavior. [11][12][13] In polar heterostructures (HSs), a general issue is the thickness of the two-dimensional gas induced at the IF, which is usually some 1-2 nm.…”

Dielectric properties of NaNbO3:SrTiO3 interface nanolayer

“…The electronic and structural properties of different charge-imbalanced NNO:STO SLs have been investigated and the detailed results can be found in Ref. 3. In order to estimate the dielectric properties of NNO:STO interfaces, here we focus on ionic positions at interfaces.…”

“…Recently, peculiar interfacial phenomena have been detected in short-period multilayers and SLs of paraelectric SrTiO 3 ͑STO͒ and NaNbO 3 ͑NNO͒, 2,3 where effects of misfit strain and ferroelectric polarization are negligible. In Ref.…”

“…It has been shown by first-principles analysis that the interfacial charge imbalance can really lead to an expansion of the unit cell ͑u.c.͒ volume. 3 In the present work, the role of NNO:STO interface in the dielectric response is investigated. The effective thickness and dielectric permittivity of the near-interface layer are determined by combining firstprinciples calculations and experimental studies.…”