Hall effect on the triangular lattice

León, Gladys; Berthod, Christophe; Giamarchi, Thierry; Millis, Andrew J.

doi:10.1103/physrevb.78.085105

Cited by 10 publications

(8 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared to a classical material, R H exhibits a strong T dependence in the whole T range, with a linear behavior at high T . This characteristic shape has also been observed in Na x CoO 2 36 and different models developed for a triangular lattice can reproduce the high T linear dependence 37–39. The importance of the triangular lattice geometry being at the origin of this linear behavior is emphasized in Ref.…”

Section: Hall Effect As a Probe Of The Thermoelectric Properties Insupporting

confidence: 54%

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties

Hébert

Kobayashi

Muguerra

et al. 2012

Physica Status Solidi (a)

View full text Add to dashboard Cite

In this paper, we show how the thermoelectric properties can be modified in crystallographic structures based on the CdI 2 type layer, by changing the block layers between these CdI 2 type layers or by going from oxides to selenides and sulfides. In the case of oxides, the unique properties generated in these structures will be demonstrated in Bi-based misfit compounds. By combining Hall effect, resistivity, and Seebeck coefficients in single crystals of this family, the importance of doping and of spin and orbital degeneracy term on the Seebeck coefficient will be shown. From this single crystal investigation, the power factor at 300 K is found to be unexpectedly constant as a function of doping. To further enhance the power factor and thus ZT, it is necessary to modify either the block layer or to perform anionic substitutions. By going from oxides to selenides and sulfides, the decrease of the ionic character can induce a decrease of electrical resistivity. Compared to oxides, the properties can generally be described in a more classical way using Boltzmann transport theory. For these materials, the critical parameter is then thermal conductivity and this quantity can be decreased as shown here by intercalating Cu between the layers (Cu x TiS 2 ), or by making solid solution such as TiS 2 À x Se x . These two approaches will be described here, leading to ZT close to 0.5 and 0.4, at 800 and 700 K, respectively.

show abstract

Section: Hall Effect As a Probe Of The Thermoelectric Properties Insupporting

confidence: 54%

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties

Hébert

Kobayashi

Muguerra

et al. 2012

Physica Status Solidi (a)

View full text Add to dashboard Cite

show abstract

“…This behavior was clearly noticed even up to much higher T in the initial experiments on a given sample (28). Such a linear increase of the Hall effect has indeed been suggested to be a specific behavior for a uniformly doped triangular metallic lattice, whatever the doping and the EC strength (29) (30). The present results do support quite generally this theoretical suggestion.…”

Section: Comparison Of Transport Properties Of Different Phasessupporting

confidence: 88%

Hall effect evidence for an interplay between electronic correlations and Na order induced electronic bands topology in NaxCoO2

Gilmutdinov

Mukhamedshin

Alloul

2020

Phys. Rev. Materials

View full text Add to dashboard Cite

The incidence of topology on the band structure and physical properties of layered compounds has been extensively studied in semimetals. How those evolve in presence of electronic correlations has been less investigated so far. In the sodium cobaltates NaxCoO2 considered here, unexpected magnetic properties associated with correlations on the Co sites have been disclosed about 15 years ago. Altogether it has also been found that various orderings of the Na atoms occur in between the CoO2 layers in the stable phases of these cobaltates. The distinct Na orders of these phases have been shown to induce specific Co charge disproportionation with large size unit cells in the CoO2 planes, linked with the diverse magnetic behaviors. This provides an original playground in the studies of interplays between topology and correlations in these layered materials. We present here transport measurements on a series of single crystals and demonstrate that we do synthetize pure phases with quite reproducible transport properties. We show that above room T those display a similar behavior whatever the Na content. On the contrary we evidence a great diversity in Hall effect low temperature dependences which underlines the specificities of the Fermi Surface reconstructions induced by the Na order. We study in some detail the difference between two metallic phases, one (x=0.77) antiferromagnetic below TN=22 K and the second (x=2/3) paramagnetic down to T=0. Both display a change of sign of Hall effect with decreasing T. We demonstrate that this can be attributed to quite distinct physical effects. For the x=0.77 phase the negative Hall effect has a non-linear field dependence and occurs in similar conditions as the anomalous Hall effect found in various magnetic metals. In the x=2/3 phase in which the Co sites are disproportionated in a kagome substructure, the singularities of the Hall effect have to be assigned with specificities of its Fermi surface. In both cases the detected Hall effect anomalies are certainly associated with the topology of their Co electronic bands.

show abstract

“…39 They reported a Hall coefficient of 12.5 Â 10 À3 cm 3 C À1 at room temperature for an epitaxial thin film sample -similar to our results for d % 0 -combined with a strong temperature dependency of R H , which cannot be explained within the simple Drude picture. In order to obtain a meaningful estimate for the charge carrier concentration via the classical relation R H ¼ 1/ne, Eng et al extrapolated their low temperature (T < 100 K) data, where the influence of electronic correlations on the Hall coefficient is negligible, 41,42 to high temperatures. They obtained an estimate for the ordinary Hall coefficient of R H ¼ 2.6 Â 10 À3 cm 3 C À1 , corresponding to a hole concentration of 0.36 per formula unit.…”

Section: Resultsmentioning

confidence: 99%

Hall effect measurements on thermoelectric Ca3Co4O9: On how to determine the charge carrier concentration in strongly correlated misfit cobaltites

Schrade

Norby

Finstad

2015

Journal of Applied Physics

View full text Add to dashboard Cite

The Hall coefficient R H and electrical conductivity of misfit calcium cobalt oxide (Ca 2 CoO 3Àd) q (CoO 2) (CCO) were measured at room temperature for different oxygen vacancy concentrations d. Based on these and numerous previous results, it is shown that the charge carrier concentrations n obtained by the classical formula R H ¼ 1/ne are between 3 and 6 Â 10 20 cm À3 and thereby much lower than those derived by other experimental techniques and fail to explain the observed electric properties of CCO. We show that the experimental results are well described using an earlier proposed t-J-model for strongly correlated electrons on a triangular lattice. The hopping parameter t for CCO was found to be % À20 K and the charge carrier concentration of fully oxidized CCO to be 5.7 Â 10 21 cm À3 (0.41 hole type carriers per formula unit), in agreement with other experimental techniques. V

show abstract

Hall effect on the triangular lattice

Cited by 10 publications

References 31 publications

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties

Hall effect evidence for an interplay between electronic correlations and Na order induced electronic bands topology in NaxCoO2

Hall effect measurements on thermoelectric Ca3Co4O9: On how to determine the charge carrier concentration in strongly correlated misfit cobaltites

Contact Info

Product

Resources

About

Hall effect on the triangular lattice

Cited by 10 publications

References 31 publications

From oxides to selenides and sulfides: The richness of the CdI2 type crystallographic structure for thermoelectric properties

From oxides to selenides and sulfides: The richness of the CdI2 type crystallographic structure for thermoelectric properties

Hall effect evidence for an interplay between electronic correlations and Na order induced electronic bands topology in NaxCoO2

Hall effect measurements on thermoelectric Ca3Co4O9: On how to determine the charge carrier concentration in strongly correlated misfit cobaltites

Contact Info

Product

Resources

About

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties

From oxides to selenides and sulfides: The richness of the CdI₂ type crystallographic structure for thermoelectric properties