NMR studies of single crystals of the topological insulator Bi2Te3 at low temperatures

Antonenko, A. O.; Charnaya, E. V.; Nefedov, D. Yu.; Podorozhkin, D. Yu.; Усков, А. В.; Бугаев, А. С.; Lee, M. K.; Chang, Lo-Yueh; Наумов, С. В.; Perevozchikova, Yu. A.; Chistyakov, V. V.; Марченкова, Е. Б.; Weber, H.W.; Huang, Jung-Chun Andrew; Марченков, В. В.

doi:10.1134/s1063783417050031

Cited by 11 publications

(3 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contemporary efforts are aimed at fabricating nanostructured thin films of Bi 2 Te 3 . A variety of techniques including solvothermal, hydrothermal, pulsed laser deposition, thermal evaporation, and electrodeposition, have been utilized in the synthesis process [49][50][51][52][53]. Among these techniques, electrodeposition holds promise for achieving uniform nanostructures of Bi 2 Te 3 owing to its advantageous characteristics, such as synthesis at low temperature; elimination of the need for a vacuum; high deposition rate; low cost; and ability to control the composition, structure, and morphology of the synthesized material.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Concentration of the Electrolyte on the Thermoelectric Properties of Electrodeposited Bi2Te3 Thin Films

Khairnar,

Kulkarni,

Lonikar

et al. 2024

Preprint

View full text Add to dashboard Cite

The current thread of study focuses on tuning the properties of nanostructured Bi2Te3 films for thermoelectric applications, by optimizing electrodeposition conditions such as the deposition potential, pH of the electrolyte, temperature and concentration of the precursors in the solvent. In this paper, small coagulated masses of Bi2Te3 dendritic nanostructures were electrodeposited on a stainless-steel substrate at previously optimized deposition potential and pH conditions while changing the concentration of Bi3+ ions in the electrolyte (varied from 2.5 mM to 15 mM). Cyclic voltammetry studies revealed that the material was deposited irreversibly at all concentrations. The effect of varying the concentration is indicated by a shift in the current peaks for oxidation and reduction. A series of scanning electron micrographs revealed the evolution of beautiful small coagulated masses of dendritic structures as a function of the concentration of electrolyte. Thermoelectric properties such as a Seebeck coefficient up to -45.81 μV/K and power factor up to 311 μW/cmK2 have been achieved for the deposited films. The results reveal significant variation in the thermoelectric properties as a function of the concentration of Bi3+ in the electrolyte through changes in the surface morphology and stoichiometry of the films. The analysis also revealed ideal concentrations of precursor ions to obtain Bi2Te3 as the dominant phase.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of the Concentration of the Electrolyte on the Thermoelectric Properties of Electrodeposited Bi2Te3 Thin Films

Khairnar,

Kulkarni,

Lonikar

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…Energy harvesting technology based on thermoelectric (TE) effects, which reversibly convert between temperature difference and electricity, can be employed as a stable and permanent energy source for self-powered systems in sensors, electronics, and machines. − To respond to the demands of small-sized and low-power consumer electronics at a low temperature range (273–473 K), thin film with sizes below few tens of micrometers to submillimeter-thick film Bi 2 Te 3 alloys for TE energy harvesting devices have recently gained considerable attention. − However, in the case of thin films, owing to their thickness limitation, a large Δ T cannot be achieved, which hinders the provision of a practically useable power. On the contrary, submillimeter-thick films can provide appropriate power when Δ T is achieved through a reasonable size. ,− …”

Section: Introductionmentioning

confidence: 99%

Synergistically Improved Thermoelectric Energy Harvesting of Edge-Oxidized-Graphene-Bridged N-Type Bismuth Telluride Thick Films

Jung

Kim

Lee

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Power generation through the thermoelectric (TE) effect in small-sized devices requires a submillimeter-thick film that is beneficial to effectively maintain ΔT compared with a micron-scale thin film. However, most TE thick films, which are fabricated using printing technologies, suffer from low electrical conductivity due to the porous structures formed after sintering of the organic binder-mixed TE ink. In this study, we report an n-type TE thick film fabricated through bar-coating of the edge-oxidizedgraphene (EOG)-dispersed Bi 2.0 Te 2.7 Se 0.3 (BTS) paste with copper dopants. We have found that EOG provides the conducting pathway for carriers through electrical bridging between the separated BTS grains in porous TE thick films. The simultaneous enhancement in electrical conductivity and the Seebeck coefficient of the EOG-bridged TE film result in a maximum power factor of 1.54 mW•m −1 •K −2 with the addition of 0.01 wt % EOG. Furthermore, the single element made of an n-type EOG-bridged BTS exhibits a superior output power of 1.65 μW at ΔT = 80 K. These values are 5 times higher than those of bare BTS films. Our results clearly indicate that the utilization of EOG with a metal dopant exerts a synergistic effect for enhancing the electrical output performance of n-type TE thick films for thermal energy harvesters.

show abstract

“…Most of the reports on NMR of topological insulators, i.e., Bi 2 Se 3 and Bi 2 Te 3 , focussed on the spin 1/2 nuclei 77 Se and 125 Te. They concerned the investigation of single crystals [9,10,11,12,13], powders [14,15,16], or nano-powders [17,18,19], and addressed relaxation, shifts, and the influence of surface states, but also the presence of a strong indirect nuclear spin coupling that gives rise to extensive NMR line broadening in Bi 2 Se 3 [10]. The understanding of NMR in strongly spin-orbit coupled systems is not well developed.…”

Section: Introductionmentioning

confidence: 99%

Unusual $^{209}$Bi NMR quadrupole effects in topological insulator Bi$_2$Se$_3$

Guehne,

Chlan,

Williams

et al. 2019

Preprint

View full text Add to dashboard Cite

Three-dimensional topological insulators are an important class of modern materials, and a strong spin-orbit coupling is involved in making the bulk electronic states very different from those near the surface. Bi 2 Se 3 is a model compound, and 209 Bi NMR is employed here to investigate the bulk properties of the material with focus on the quadrupole splitting. It will be shown that this splitting measures the energy band inversion induced by spin-orbit coupling in quantitative agreement with first-principle calculations. Furthermore, this quadrupole interaction is very unusual as it can show essentially no angular dependence, e.g., even at the magic angle the first-order splitting remains. Therefore, it is proposed that the magnetic field direction is involved in setting the quantization axis for the electrons, and that their life time leads to a new electronically driven relaxation mechanism, in particular for quadrupolar nuclei like 209 Bi. While a quantitative understanding of these effects cannot be given, the results implicate that NMR can become a powerful tool for the investigation of such systems.

show abstract

NMR studies of single crystals of the topological insulator Bi2Te3 at low temperatures

Cited by 11 publications

References 13 publications

Effect of the Concentration of the Electrolyte on the Thermoelectric Properties of Electrodeposited Bi2Te3 Thin Films

Effect of the Concentration of the Electrolyte on the Thermoelectric Properties of Electrodeposited Bi2Te3 Thin Films

Synergistically Improved Thermoelectric Energy Harvesting of Edge-Oxidized-Graphene-Bridged N-Type Bismuth Telluride Thick Films

Unusual $^{209}$Bi NMR quadrupole effects in topological insulator Bi$_2$Se$_3$

Contact Info

Product

Resources

About