Magnetic orders and electronic structure in LaMnO3/SrTiO3 superlattices

Liu, H. M.; Y., C.; Zhou, Pengfei; Dong, Shuai; Liu, J.-M.

doi:10.1063/1.4793705

Cited by 11 publications

(6 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The states of Ti are mostly above the Fermi level and thus empty. The charge transfer from Mn to Ti across the interface is evaluated by integrating the pDOS of Ti, which is only ∼ 0.03 electron per interfacial Ti (a negligible value), in consistent with previous reports [57,58]. In experimental sample growth process of oxides, oxygen vacancies (V O 's) seem to be inevitable, more or less [34,[76][77][78][79][80].…”

Section: Iiib Lmo/sto Heterostructuressupporting

confidence: 84%

“…In this work, the structural and magnetic properties of (001)-oriented vacuum/(LMO) n /(STO) 2 heterostructures will be studied using DFT calculation, in order to reveal the mechanism behind the thickness dependent magnetic transition. It should be noted although there have been many DFT studies on strained LMO, some of these calculations have not really put STO layer and vaccum into considerations [38][39][40], or those previous DFT methods would be failed to correctly describe the strain effect in LMO/STO heterostructures [57,58], as clarified in the following section. In addition, the (LMO) n /(STO) m superlattices without surface will also be calculated.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Appearance and disappearance of ferromagnetism in ultrathin LaMnO3 on SrTiO3 substrate: A viewpoint from first principles

An¹,

Weng²,

Zhang³

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

The intrinsic magnetic state (ferromagnetic or antiferromagnetic) of ultra-thin LaMnO3 films on the mostly used SrTiO3 substrate is a long-existing question under debate. Either strain effect or non-stoichiometry was argued to be responsible for the experimental ferromagnetism. In a recent experiment [Science 349, 716 (2015)], one more mechanism, namely the self-doping due to polar discontinuity, was argued to be the driving force of ferromagnetism beyond the critical thickness. Here systematic first-principles calculations have been performed to check these mechanisms in ultra-thin LaMnO3 films as well as superlattices. Starting from the very precise descriptions of both LaMnO3 and SrTiO3, it is found that the compressive strain is the dominant force for the appearance of ferromagnetism, while the open surface with oxygen vacancies leads to the suppression of ferromagnetism. Within LaMnO3 layers, the charge reconstructions involve many competitive factors and certainly go beyond the intuitive polar catastrophe model established for LaAlO3/SrTiO3 heterostructures. Our study not only explains the long-term puzzle regarding the magnetism of ultra-thin LaMnO3 films, but also shed light on how to overcome the notorious magnetic dead layer in ultra-thin manganites.

show abstract

Section: Iiib Lmo/sto Heterostructuressupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Appearance and disappearance of ferromagnetism in ultrathin LaMnO3 on SrTiO3 substrate: A viewpoint from first principles

An¹,

Weng²,

Zhang³

et al. 2017

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…The off-centering is generally enhanced at the interfaces when n increases and reduced when m increases. It is known that the properties of SrTiO 3 are very sensitive to dopants and external perturbations30 so that it cannot surprise that the superlattices react similarly31. We also note that we obtain for bulk SrTiO 3 a ferroelectric distortion of 0.03 Å, which is a known artefact of the employed methodology32.…”

Section: Resultsmentioning

confidence: 50%

Trends in (LaMnO3)n/(SrTiO3)m superlattices with varying layer thicknesses

Jiwuer

Cossu

Schwingenschlögl

2015

Sci Rep

View full text Add to dashboard Cite

We investigate the thickness dependence of the structural, electronic, and magnetic properties of (LaMnO3)n/(SrTiO3)m (n, m = 2, 4, 6, 8) superlattices using density functional theory. The electronic structure turns out to be highly sensitive to the onsite Coulomb interaction. In contrast to bulk SrTiO3, strongly distorted O octahedra are observed in the SrTiO3 layers with a systematic off centering of the Ti atoms. The systems favour ferromagnetic spin ordering rather than the antiferromagnetic spin ordering of bulk LaMnO3 and all show half-metallicity, while a systematic reduction of the minority spin band gaps as a function of the LaMnO3 and SrTiO3 layer thicknesses originates from modifications of the Ti dxy states.

show abstract

“…Varied nature of magnetic and electronic behavior of the LMO/STO interfaces have been reported, depending on the relative thickness of LMO and STO and their geometry. [6][7][8][9][10][11][12] Among all, the most intriguing is the suggestion of ferromagnetic insulating behavior, which has been reported for LMO/STO superlattices when LMO and STO have comparable thicknesses, 12 as well as in thin-film/substrate geometries. 10 This is counter-intuitive, since ferromagnetism is commonly associated with metallicity and antiferromagnetism is typical for insulators.…”

Section: Introductionmentioning

confidence: 99%

Electronic and magnetic state of LaMnO3 epitaxially strained on SrTiO3 : Effect of local correlation and nonlocal exchange

et al. 2019

View full text Add to dashboard Cite

Motivated by the puzzling report of the observation of a ferromagnetic insulating state in LaMnO3/SrTiO3 heterostructures, we calculate the electronic and magnetic state of LaMnO3, coherently matched to a SrTiO3 square substrate within a "strained-bulk" geometry. We employ three different density functional theory based computational approaches: (a) density functional theory (DFT) supplemented with Hubbard U (DFT+U ), (b) DFT + dynamical mean field theory (DMFT), and (c) a hybrid functional treatment of the exchange-correlation functional. While the first two approaches include local correlations and exchange at Mn sites, treated in a static and dynamic manner, respectively, the last one takes into account the effect of non-local exchange at all sites. We find in all three approaches that the compressive strain induced by the square substrate of SrTiO3 turns LaMnO3 from an antiferromagnet with sizable orbital polarization to a ferromagnet with suppressed Jahn-Teller distortion in agreement with experiment. However, while both DFT+U and DFT+DMFT provide a metallic solution, only the hybrid calculations result in an insulating solution, as observed in experiment. This insulating behavior is found to originate from an electronic charge disproportionation. Our conclusions remain valid when we investigate LaMnO3/SrTiO3 within the experimental set-up of a superlattice geometry using DFT+U and hybrid calculations. arXiv:1907.11979v1 [cond-mat.mtrl-sci]

show abstract

Magnetic orders and electronic structure in LaMnO3/SrTiO3 superlattices

Cited by 11 publications

References 30 publications

Appearance and disappearance of ferromagnetism in ultrathin LaMnO3 on SrTiO3 substrate: A viewpoint from first principles

Appearance and disappearance of ferromagnetism in ultrathin LaMnO3 on SrTiO3 substrate: A viewpoint from first principles

Trends in (LaMnO3)n/(SrTiO3)m superlattices with varying layer thicknesses

Electronic and magnetic state of LaMnO3 epitaxially strained on SrTiO3 : Effect of local correlation and nonlocal exchange

Contact Info

Product

Resources

About