Structural details and magnetic order of<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">Sr</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:

Caciuffo, R.; Rinaldi, D.; Barucca, G.; Mira, J.; Rivas, José; Señarı́s-Rodrı́guez, M. A.; Radaelli, P. G.; Fiorani, D.; Goodenough, John B.

doi:10.1103/physrevb.59.1068

Cited by 340 publications

(202 citation statements)

References 36 publications

Supporting

Mentioning

180

Contrasting

Unclassified

Order By: Relevance

“…13 were found to be significantly better than fits done based on the Gruneisen formulation using the Einstein model for specific heat. [9,17,36] Unlike the Gruneisen fits, the power law fits are able to account for the sharp increase in slope near T 0 and the negative curvature for 50 ≤ T ≤ 300 K. Similar qualitative behavior can be seen in the w = 1.0 samples; they are also well fit by the power law. Although Radaelli et al fit their lattice parameters in the context of thermal excitations, it is difficult to assess those fits in the range we are examining because of the sparse temperature sampling.…”

Section: Figsupporting

confidence: 61%

“…In the CoO 6 octahedra, the Co 3d and the O 2p orbitals hybridize to form lower energy t 2g and higher energy e g orbitals. Within this localized spin excitation model, there has been a long-standing debate as to whether the electrons in these orbitals -presumed to be paired in a S = 0, low-spin (LS) configuration -excite into either a S = 1, intermediatespin (IS), a S = 2 high-spin (HS) configuration, or a mixture of the two [4][5][6][7][8][9]. In the LS configuration (t 6 2g e 0 g ), all of the Co 3+ electrons are paired together in the lowest energy orbitals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

Durand

Hamil

Belanger

et al. 2015

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Bulk LawCoO3 particles with w = 1.1, 1.0, 0.9, 0.8, and 0.7 were synthesized using starting materials with varying molar ratios of La2O3 and Co3O4. The resulting particles are characterized as LaCoO3 crystals interfaced with a crystalline Co3O4 phase. X-ray and neutron scattering data show little effect on the average structure and lattice parameters of the LaCoO3 phase resulting from the Co3O4 content, but magnetization data indicate that the amount of Co3O4 strongly affects the ferromagnetic ordering at the interfaces below TC ≈ 89 K. In addition to ferromagnetic long-range order, LaCoO3 exhibits antiferromagnetic behavior with an unusual temperature dependence. The magnetization for fields 20 Oe ≤ H ≤ 5 kOe is fit to a combination of a power law ((T − TC )/TC ) β behavior representing the ferromagnetic long-range order and sigmoid-convoluted Curie-Weiss-like behavior representing the antiferromagnetic behavior. The critical exponent β = 0.63 ± 0.02 is consistent with 2D (surface) ordering. Increased Co3O4 correlates well to increased ferromagnetism. The weakening of the antiferromagnetism below T ≈ 40 K is a consequence of the lattice reaching a critical rhombahedral distortion as T is decreased for core regions far from the Co3O4 interfaces. We introduce a model that describes the ferromagnetic behavior of the interface regions and the unusual antiferromagnetism of the core regions.

show abstract

Section: Figsupporting

confidence: 61%

Section: Introductionmentioning

confidence: 99%

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

Durand

Hamil

Belanger

et al. 2015

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…A signature characteristic of cobalt oxides that distinguishes them from the other transition metal oxides is that Co ions are all susceptible to having multiple valence and/or spin states. [1][2][3][4][5][6][7] The different electronic configurations can appear as a result of the interplay between the crystal field, caused by the local atomic environment, and the interatomic exchange interaction. Perhaps the most extensively studied cobaltates in which the polyvalency and multi-spin states come to play to produce complex phase diagrams have been La 2−x Sr x CoO 4 , 1-4 and La 1−x Sr x CoO 3 , 5-8 .…”

Section: Introductionmentioning

confidence: 99%

Structural and magnetic properties of the cobaltate series (BaSr)4−xLa2xCo

et al. 2012

View full text Add to dashboard Cite

Structural and magnetic properties of the new cobaltate series (BaSr) We report the structural and magnetic properties of a new class of cobaltates with the chemical formula (BaSr)4−xLa2xCo4O15 (x = 0, 0.5 and 1). These compounds crystallize in a hexagonal structure in which cobalt ions are distributed among two distinct crystallographic sites with different oxygen coordination. Three Co-O tetrahedra and one octahedron are linked by shared oxygen atoms to form Co4O15 clusters, which are packed together into a honeycomb-like network. Partial substitution of Sr and/or Ba atoms by La allows one to adjust the degree of Co valence mixing, but all compositions remain subject to a random distribution of charge. Magnetic susceptibility together with neutron scattering measurements reveal that all studied specimens are characterized by competing ferro-and antiferro-magnetic exchange interactions that give rise to a three dimensional Heisenberg spin-glass state. Neutron spectroscopy shows a clear trend of slowing down of spindynamics upon increasing La concentration, suggesting a reduction in charge randomness in the doped samples.

show abstract

“…In the Co-based perovskite-like oxides the competition between the crystal-field splitting and the intra-atomic Hund's coupling of Co ions lead to a variety of magnetic and electronic phase transitions among the high-, intermediate-and low-spin configurations of Co 3 + and Co 4 + ions. The (LaixA,)CoO 3 system also displays many new and unusual behaviors open to study.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Properties and Scaling Behavior in Perovskite–like La_0.7(Ba_1−xPb_x)_0.3CoO₃ System

2001

View full text Add to dashboard Cite

In this study, we used x-ray diffraction patterns and dc magnetic measurements to investigate the crystallographic structure, magnetic properties and scaling behavior of the distorted perovskite La0.7(Ba1−xPbx)0.3CoO3 (0 ≤ x ≤ 0.5) system with a constant ratio of Co4+/Co3+. Samples with x = 0.0 and 0.1 were crystallized in the cubic structure with a ∼ 7.76 Å whereas samples with x ≥ 0.2 were crystallized in an orthorhombic Pbnm space group with a ∼ b ∼ 5.50 Å and c ∼ 7.85 Å. For all our samples the spin-glass-like behavior were observed in low temperature and low field ranges. The Pb2+ substitution on Ba2+ site does not significantly affect the ferromagnetic transition temperature TC, but does introduce large variation in the magnetic strength. In both the ferromagnetic and paramagnetic states the minimum values of the average effective moments provided by every Co ion occur at x = 0.3. We also observed the scaling behaviors of magnetic data in all samples. The derived values of the critical exponents (β, γ, δ) were consistent with those predicted by mean field theory and a three-dimensional Heisenberg model.

show abstract

Structural details and magnetic order ofLa1−xSrxCoO

Cited by 340 publications

References 36 publications

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

Structural and magnetic properties of the cobaltate series (BaSr)4−xLa2xCo

Magnetic Properties and Scaling Behavior in Perovskite–like La_0.7(Ba_1−xPb_x)_0.3CoO₃ System

Contact Info

Product

Resources

About

Structural details and magnetic order ofLa1−xSrxCoO

Cited by 340 publications

References 36 publications

The effects of Co3O4on the structure and unusual magnetism of LaCoO3

The effects of Co3O4on the structure and unusual magnetism of LaCoO3

Structural and magnetic properties of the cobaltate series (BaSr)4−xLa2xCo

Magnetic Properties and Scaling Behavior in Perovskite–like La0.7(Ba1−xPbx)0.3CoO3 System

Contact Info

Product

Resources

About

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

The effects of Co₃O₄on the structure and unusual magnetism of LaCoO₃

Magnetic Properties and Scaling Behavior in Perovskite–like La_0.7(Ba_1−xPb_x)_0.3CoO₃ System