Spin and orbital disordering by hole doping in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi mathvariant="normal">P</mml:mi><mml:msub><mml:mi mathvariant="normal">r</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:mi mathvariant="normal">C</mml:mi><mml:msub><mml:mi mathvariant="normal">a</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:mi mathvariant="normal">V</mml:mi><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>3</mml:mn><

Reehuis, M.; Ulrich, C.; Abdala, Paula M.; Pattison, Philip; Khaliullin, Giniyat; Fujioka, Jun; Miyasaka, S.; Tokura, Y.; Keimer, B.

doi:10.1103/physrevb.94.104436

Cited by 14 publications

(21 citation statements)

References 42 publications

(96 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We point out that despite an antiferromagnetic spin order expected at low temperature, antisymmetric spin-spin interactions via Dzyaloshinskii-Moriya interactions promote a canted and uncompensated spin state [19,36,37]. Together with the spin imbalance of the V 3d-V 3d sublattices [38], V 3d-R 4 f magnetic exchange interactions [39][40][41] may also strengthen the ferromagneticlike signal as observed here for PVO compared to LVO, whose magnetization is about 100 times lower. Indeed, Pr 3+ has two electrons in the 4 f orbitals whereas LVO has none.…”

Section: Resultssupporting

confidence: 49%

Epitaxial growth and structure of LaVO3 and PrVO3 thin films

Masset

Copie

Ghanbaja

et al. 2020

Phys. Rev. Materials

View full text Add to dashboard Cite

We report on the epitaxial growth of PrVO 3 and LaVO 3 by molecular beam epitaxy on (001)-oriented SrTiO 3 substrates. We show that a high control of the deposition is achieved and leads to a highly reproducible layer-by-layer growth mode. We evidence also the effect of epitaxial strain on the magnetic properties of the epitaxial films. High-resolution transmission electron microscopy and scanning transmission electron microscopy observations reveal that an antipolar motion of the rare earth atoms exists in both LaVO 3 and PrVO 3 thin films. The investigation of the structural distortions and atomic displacements in the vanadate thin films may be generalized to other orthorhombic perovskite oxides and contributes to the search of ferroelectricity by design in symmetry-breaking magnetic oxide superlattices.

show abstract

Section: Resultssupporting

confidence: 49%

Epitaxial growth and structure of LaVO3 and PrVO3 thin films

Masset

Copie

Ghanbaja

et al. 2020

Phys. Rev. Materials

View full text Add to dashboard Cite

show abstract

“…The combination of spin and orbital degrees of freedom triggers spin-orbital (SO) polarons [59][60][61][62]. We shall discuss in this work why small SO polarons in the insulating regime of cubic vanadates [58,63] are much more strongly bound to charge defects than spin polarons in high-T c materials [64,65]. The reduced mobility of doped holes or electrons inside the SO polarons implies a weaker screening of defect potentials by the doped charge carriers and thus provides an arXiv:1710.05171v1 [cond-mat.str-el] 14 Oct 2017 explanation for the shift of the insulator to metal transition towards high doping concentrations in the vanadates.…”

Section: Introductionmentioning

confidence: 99%

Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy

2018

View full text Add to dashboard Cite

We explore the effects of disordered charged defects on the electronic excitations observed in the photoemission spectra of doped transition metal oxides in the Mott insulating regime by the example of the R1−xCaxVO3 perovskites, where R = La, . . . , Lu. A fundamental characteristic of these vanadium d 2 compounds with partly filled t2g valence orbitals is the persistence of spin and orbital order up to high doping, in contrast to the loss of magnetic order in high-Tc cuprates at low defect concentration. We demonstrate that the disordered electronic structure of doped Mott-Hubbard insulators can be obtained with high precision within the unrestricted Hartree-Fock approximation. In particular: (i) the atomic multiplet excitations in the inverse photoemission spectra and the various defect-related states and satellites are well reproduced, (ii) a robust Mott gap survives up to large doping, and (iii) we show that the defect states inside the Mott gap develop a soft gap at the Fermi energy. The soft defect states gap, that separates the highest occupied from the lowest unoccupied states, can be characterized by a shape and a scale parameter extracted from a Weibull statistical sampling of the density of states near the chemical potential. These parameters provide a criterion and a comprehensive schematization for the insulator-metal transition in disordered systems. We demonstrate that charge defects trigger small spinorbital polarons, with their internal kinetic energy responsible for the opening of the soft defect states gap. This kinetic gap survives disorder fluctuations of defects and is amplified by the long-range e-e interactions, whereas in the atomic limit we observe a Coulomb singularity. The small size of spin-orbital polarons is inferred by an analysis of the inverse participation ratio which explains the origin of the robustness of spin and orbital order. Using realistic parameters for the perovskite vanadate system La1−xCaxVO3, we show that its soft gap is well reproduced as well as the marginal doping dependence of the position of the chemical potential relative to the center of the lower Hubbard band. The present theory uncovers also the reasons why the d 1 → d 0 satellite excitations, which directly probe the effect of the random defect fields on the polaron state, are not well resolved in the available experimental photoemission spectra for La1−xCaxVO3.

show abstract

“…Naturally, vanadates are considered to be model canonical systems for investigating a rich variety of outstanding magnetic and electrical behaviors originating from the interconnected knot of spin, charge, orbital and lattice correlations of the V t 2g electrons [8][9][10][11][12][13] . The t 2g valence electrons of the V ions (V 3+ : t 2 2g /V 4+ : t 1 2g ) undergo significantly lower noncubic crystal field splitting, as compared to that of the e g manifold in isostructural manganites, resulting in the comparable energy separation of orbital levels to the spin interactions 7,11 .…”

Section: Introductionmentioning

confidence: 99%

Colossal electroresistance response accompanied by metal-insulator transition in a mixed-valent vanadate

Saha

Bandyopadhyay²,

Schiesaro³

et al. 2021

Phys. Rev. B

View full text Add to dashboard Cite

Colossal electroresistance (CER) in manganites, i.e., a large change in electrical resistance under the influence of either an applied electric field or an applied electric current, has often been described as complimentary to the colossal magnetoresistance (CMR) effect. Mixed valent vanadates with active t 2g and empty e g orbitals, unlike manganites, have not naturally been discussed in this context, as double exchange based CMR is not realizable in them. However, presence of coupled spin and orbital degrees of freedom, metal-insulator transition (MIT) accompanied by orbital order-disorder transition, etc., anyway make the vanadates an exciting group of materials. Here we probe a Fe-doped hollandite lead vanadate PbFe 1.75 V 4.25 O 11 (PFVO), which exhibits a clear MIT as a function of temperature. Most importantly, a giant fall in the resistivity, indicative of a CER, as well as a systematic shift in the MIT towards higher temperature are observed as a function of applied electric current. Detailed structural, magnetic, thermodynamic and transport studies point towards a complex interplay between orbital order/disorder effect, MIT and double exchange in this system.

show abstract

Spin and orbital disordering by hole doping inPr1−xCaxVO3<

Cited by 14 publications

References 42 publications

Epitaxial growth and structure of LaVO3 and PrVO3 thin films

Epitaxial growth and structure of LaVO3 and PrVO3 thin films

Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy

Colossal electroresistance response accompanied by metal-insulator transition in a mixed-valent vanadate

Contact Info

Product

Resources

About