Competing electronic ground states in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">La</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mi>−</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Ca</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">CoO</mml:mi></mml:mro

Mitchell, J. F.; Short, S.

doi:10.1103/physrevb.69.054401

Cited by 62 publications

(42 citation statements)

References 32 publications

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“…It is now established that La 0.5 Sr 0.5 CoO 3 exhibits a glassy magnetic behaviour (Wu et al 2005). Recent studies of the magnetic and electrical properties of several members of the Ln 1Kx A x CoO 3 family have revealed that they are electronically phase-separated (Burley et al 2004;Kundu et al 2005a;Wu et al 2005). The phase separation is favoured by small hr A i as well as size disorder (Kundu et al 2006).…”

Section: Electronic Phase Separation In Rare-earth Cobaltatesmentioning

confidence: 99%

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Shenoy

Rao

2007

Phil. Trans. R. Soc. A.

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Transition metal oxides, such as the mixed-valent rare-earth manganites Ln (1Kx) A x MnO 3 (Ln, rare-earth ion, and A, alkaline-earth ion), show a variety of electronic orders with spatially correlated charge, spin and orbital arrangements, which in turn give rise to many fascinating phenomena and properties. These materials are also electronically inhomogeneous, i.e. they contain disjoint spatial regions with different electronic orders. Not only do we observe signatures of such electronic phase separation in a variety of properties, but we can also observe the different 'phases' visually through different types of imaging. We discuss various experiments pertaining to electronic orders and electronic inhomogeneities in the manganites and present a discussion of theoretical approaches to their understanding. It is noteworthy that the mixed-valent rare-earth cobaltates of the type Ln (1Kx) A x CoO 3 also exhibit electronic inhomogeneities just as the manganites.

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Section: Electronic Phase Separation In Rare-earth Cobaltatesmentioning

confidence: 99%

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Shenoy

Rao

2007

Phil. Trans. R. Soc. A.

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“…Moreover, Nagaev et al [11] have predicted that magnetic exciton formation is the precursor for magneto-electronic phase separation at high hole (electron) densities. Such a phase separation has been observed in LaCoO 3 doped with divalent cations such as Sr [12,13] and Ca [14]. The nature of a magnetic polaron or exciton implies that it may be most easily observed in a system displaying a diamagnetic ground state, making LaCoO 3 an ideal candidate to study such an defect-driven magnetic state.…”

mentioning

confidence: 99%

Observation of magnetic excitons in LaCoO ₃

et al. 2005

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. -An impurity-driven magnetic phase transition has been investigated in LaCoO3 at temperatures below that of the thermally induced spin state transition of the Co 3+ ion. We have discovered a saturating component of the magnetisation, which we attribute to previously unobserved interactions between magnetic excitons. These conclusions are confirmed by muon spin spectroscopy which indicates an ordering temperature of 50 K in both the transverse and zero-field configurations. Low-energy muon measurements demonstrate that the magnetic behaviour is independent of implantation energy and hence a property of the bulk of the material. The magnetic exciton formation is attributed to the interaction between electrons bound at oxygen vacancies and neighbouring cobalt ions, and is proposed as the precursor to the magneto-electronic phase separation recently observed in doped lanthanum cobaltite.Introduction. -LaCoO 3 is unique among the LaMO 3 family (where M is a transition metal element) as it undergoes a thermally driven spin state transition. This occurs because the crystal-field splitting of the d-levels of the Co 3+ ions is only slightly greater than Hund's exchange energy, leading to a situation where a small input of thermal energy can lead to the occupation of a higher spin state. Explicitly, a transition from a Co 3+ low spin (LS) S = 0, t 2g 6 e g 0 , state to an intermediate spin (IS) S = 1, t 2g 5 e g 1 , state occurs at around 90 K, although the exact nature of the transition is still a matter of some contention [1][2][3][4][5][6][7][8][9]. However, the low-temperature (T < 35 K) magnetic properties of LaCoO 3 are usually dominated by a Curie-like magnetic susceptibility, which is generally acknowledged to be related to defects. In particular, this "Curie tail" has been ascribed to paramagnetic impurities, ferromagnetic regions at the surface [10], and also to the formation of high spin (S = 16) magnetic polarons in LaCoO 3 [1]. Nagaev et al. [11] have also proposed that the paramagnetic centres responsible for the Curie tail are magnetic polarons, although strictly they should be labeled "magnetic excitons". In this model localized holes (electrons) bound to cobalt ions or oxygen interstitials

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“…The competition between different spin states has caused large controversy in the literature previously [10,[12][13][14][15][16][17][18][19], but in most studies only the case of LaCoO3 has been considered. Different studies favor either a LS to IS or a LS to HS state transition by heating across Ts1 ≈ 75 K [20][21][22][23][24]. Furthermore, a low temperature magnetic defect structure has been commonly observed in LaCoO3, which can be explained by the existence of magnetic polarons or excitons [24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Microwave-Assisted Synthesis, Microstructure, and Magnetic Properties of Rare-Earth Cobaltites

et al. 2016

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Citation for published item:quti¡ errez eij sD tuli nd r doEqonj lD tes¡ us nd ¡ evil fr ndeD h vid nd erryD s n nd wor¡ nD imilio nd hmidtD iner @PHIUA 9wi row veE ssisted synthesisD mi rostru tureD nd m gneti properties of r reEe rth o ltitesF9D snorg ni hemistryFD ST @IAF ppF TPUETQQF Further information on publisher's website:This document is the Accepted Manuscript version of a Published Work that appeared in nal form in Inorganic Chemistry, copyright c 2016 American Chemical Society after peer review and technical editing by the publisher. To access the nal edited and published work see https://doi.org/10.1021/acs.inorgchem.6b02557. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractThe series of perovskite rare-earth (RE) doped cobaltites (RE)CoO3 (RE = La -Dy) was prepared by microwave-assisted synthesis. The crystal structure undergoes a change of symmetry depending on the size of the RE cation. LaCoO3 is rhombohedral, S.G. , while for the rest of the RE series (Pr -Dy) the symmetry is orthorhombic, S.G. Pnma (No. 62). The crystal structure obtained by X-Ray diffraction was confirmed by high resolution transmission electron microscopy, which yielded a good match between experimental and simulated images. It is further shown that the well-known magnetism in LaCoO3, which involves a thermally induced Co 3+ (d 6 ) low spin to intermediate or high spin state transition, is strongly modified by RE-doping and a rich variety of magnetic order has been detected across the series.

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Competing electronic ground states inLa1−xCaxCoO

Cited by 62 publications

References 32 publications

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Observation of magnetic excitons in LaCoO ₃

Microwave-Assisted Synthesis, Microstructure, and Magnetic Properties of Rare-Earth Cobaltites

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Competing electronic ground states inLa1−xCaxCoO

Cited by 62 publications

References 32 publications

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Electronic phase separation and other novel phenomena and properties exhibited by mixed-valent rare-earth manganites and related materials

Observation of magnetic excitons in LaCoO 3

Microwave-Assisted Synthesis, Microstructure, and Magnetic Properties of Rare-Earth Cobaltites

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Observation of magnetic excitons in LaCoO ₃