Preparation of Cobalt doped Bi2Se3 nano-topological insulators

Ashoush, M. A.; El-Okr, Mohamed; El-Fattah, Zakaria M. Abd

doi:10.1007/s10854-016-5970-7

Cited by 4 publications

(6 citation statements)

References 16 publications

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“…Accordingly, XRD pattern clearly reveals that the synthesized Co 0.1 Bi 2 Se 3 sample is single crystalline in nature and oriented in c-axis, similar to the pure Bi 2 Se 3 sample [42]. (5) for Co added Bi 2 Se 3 was observed, which is in agreement to the earlier reported data [29][30][31][32][33]. Both the increment and decrement in the refined lattice constants are opposite to those observed in topological superconductors (TSCs).…”

Section: Resultssupporting

confidence: 87%

“…can bring about magnetic ordering, which may further enable to observe different exotic phenomena such as anomalous quantized Hall (AQH) state, magnetic monopole, topological magneto electric effect and the Faraday-Kerr effects [14][15][16][17][18][19][20][21]. In this regards, till date, several studies have been reported, which addresses the effect of magnetic ordering in various TIs viz., ferromagnetism (FM) has been observed in Cr doped Bi 2 Te 3 and Bi 2 Se 3 thin film [22][23][24], Fe doped Bi 2 Se 3 nanoribbons [25,26], Mn and V doped Bi 2 Se 3 thin films [27,28], Co doped Bi 2 Se 3 [29][30][31][32][33], Mn and Ni doped Bi 2 Se 3 [34][35][36], Fe doped Bi 2 Te 3 [37], Mn doped bulk Bi 2 Te 3 [38] and Fe and Co doped Sb 2 Te 3 [39,40].…”

Section: Introductionmentioning

confidence: 99%

“…Among the various discovered TIs (Bi 1-x Sb x , Bi 2 Te 3 , Bi 2 Se 3 , Sb 2 Te 3 ), Bi 2 Se 3 is one of the most popular and widely studied 3D TI due to the presence of a single surface Dirac cone along with a large bulk band gap of 0.3eV, promising for room temperature applications [4,15]. Although Co doping has been done earlier in Bi 2 Se 3 [29][30][31][32][33],…”

Section: Introductionmentioning

confidence: 99%

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Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Sultana

Gurjar

Patnaik

et al. 2019

J Supercond Nov Magn

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We report the crystal growth as well as transport properties of Co added Bi 2 Se 3 (Co 0.1 Bi 2 Se 3 ) single crystals. The values of the lattice parameters a and b for Co added sample were observed to increase from a = b = 4.14(2) Å to 4.16(3) Å, whereas the c value decreased marginally from 28.70(3) Å to 28.69(5) as compared to the pure Bi 2 Se 3 . The Raman spectroscopy displayed higher Raman shift of corresponding A 1g 1 , Eg 2 and A 1g 2 vibrational modes for Co 0.1 Bi 2 Se 3 , and the resistivity curves with and without applied magnetic field shows a metallic behaviour. Both the crystals were subjected to magnetoresistance (MR) measurements under applied fields of 14Tesla. The value of MR is found to decrease from about 380% (5K, 14 Tesla) for Bi 2 Se 3 to 200% for Co 0.1 Bi 2 Se 3 . To elaborate the transport properties of pure and Co added Bi 2 Se 3 crystals, the magneto-conductivity is fitted to the HLN (Hikami Larkin Nagaoka) equation and it is found that the charge conduction is mainly dominated by surface driven WAL (weak anti-localization) with negligible bulk WL (weak localization) contribution in both crystals alike. The MH curves of Co 0.1 Bi 2 Se 3 crystal at different temperatures displayed a combination of both ferromagnetic and diamagnetic behaviour. On the other hand, the Electron Paramagnetic Resonance (EPR) revealed that pure Bi 2 Se 3 is diamagnetic whereas, Co orders ferro-magnetically with resonating field around 3422Oe at room temperature. The calculated value of Lande "g" factor is around 2.04 ± 0.05. Summarily, the short letter discusses the interesting magnetoconductivity and complex magnetism of Co in Co 0.1 Bi 2 Se 3 .

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Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Sultana

Gurjar

Patnaik

et al. 2019

J Supercond Nov Magn

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“…According to a recent report, the doping of Fe can improve the electrical and thermal transport performance of Bi 0.48 Sb 1.52 Te 3 compounds, but the effects of the magnetic element doping on the TE properties are still not well addressed . While for the Co dopant, it can lead to not only strong electron–phonon coupling in FeSi but also improved pseudocapacitive performances of Cu 2 S and Bi 2 Se 3 systems. , In addition, the microstructure and TE performance of the Bi 0.5 Sb 1.5 Te 3 sample doped with magnetic ions have been investigated in a magnetostatic field . However, as far as we know, systematical investigation, especially, the comparison between magnetic and nonmagnetic elements doping in p-type Bi 0.5 Sb 1.5 Te 3 alloys have been rarely reported.…”

Section: Introductionmentioning

confidence: 99%

Precise Regulation of Carrier Concentration in Thermoelectric BiSbTe Alloys via Magnetic Doping

Wei

Wang

Zhang

et al. 2020

ACS Appl. Mater. Interfaces

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The Bi 2 Te 3 -based alloy is the best commercial thermoelectric material around room temperature, although it is extremely difficult to further improve its thermoelectric performance. In this work, we demonstrate that magnetic doping is an effective strategy to regulate the thermoelectric performance of p-type Bi 0.5 Sb 1.5 Te 3 . According to our experiments, it is much more difficult for ferromagnetic Fe/Co to enter the Bi 0.5 Sb 1.5 Te 3 lattice in comparison with diamagnetic Pb, which can be understood by the "like dissolves like" rule. At the same doping content, Fe and Co provide much lower hole carriers than Pb due to their larger carrier thermal activation energies, indicating that Fe and Co as dopants are very applicable for the fine regulation of the carrier concentration. The Fe/Co-doped samples have higher Seebeck coefficients but less carrier mobilities than the Pb-doped sample since the doped magnetic atoms induce additional carrier scattering. Beyond the solid solubility limit, excess Fe/ Co represents as the impurity, which can maintain a high carrier concentration due to the metal−semiconductor contact. Finally, the zT values of ∼1.05 and 1.15 near room temperature have been achieved for the samples with 1.71 at. % Co and 1.80 at. % Fe, respectively.

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“…There already exist some published reports on magnetically (Mn, Ni, Fe, Cr, V and Co) doped TIs, which focus on describing the effects of magnetic impurities, or discussing typical ferromagnetism on Dirac like conducting surface states in various TIs viz. Bi 2 Se 3 , Bi 2 Te 3 and Sb 2 Te 3 [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. Till date, a very few reports have discussed on the magneto transport behaviour of Eu doped Bi 2 Se 3 thin films [45,46].…”

Section: Introductionmentioning

confidence: 99%

Structural, surface morphology and magneto-transport properties of self flux grown Eu doped Bi₂Se₃ single crystal

Sultana¹,

Gurjar²,

Gahtori³

et al. 2019

Mater. Res. Express

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Here, we report the effect of europium (Eu) doping in Bi 2 Se 3 topological insulator (TI) by using different characterization techniques viz. X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDXA) and magneto-transport measurements. Good quality Eu doped Bi 2 Se 3 (Eu 0.1 Bi 1.9 Se 3 ) single crystal is grown by the self flux method through the solid state reaction route. Single crystal XRD pattern displayed the high crystalline quality of the Eu 0.1 Bi 1.9 Se 3 sample along (00l) alignment whereas; the powder XRD confirmed the rhombohedral crystal structure without any impurity phases. SEM images exhibited a layered slab like structure stacked one over the other whereas; EDXA measurements confirmed the chemical composition of Eu 0.1 Bi 1.9 Se 3 sample. Further, the EDXA mapping showed the homogeneous distribution of Bi, Se and Eu elements. Temperature dependent electrical resistivity curves revealed a metallic behaviour both in the presence and absence of applied magnetic field. Magneto-transport measurements showed a decrease in the magneto-resistance (MR) value of the Eu 0.1 Bi 1.9 Se 3 sample (~32% at 5K) in comparison to the pure Bi 2 Se 3 sample (~80% at 5K). For, Eu 0.1 Bi 1.9 Se 3 sample, a complex crossover between WL and WAL phenomenon was observed at lower applied magnetic fields, whereas the same was absent in case of the pristine one. Further, HLN (Hikami Larkin Nagaoka) fitted magneto-conductivity (MC) analysis revealed a competing weak anti localization (WAL) and weak localization (WL) behaviour. Summarily, in the present work we study the structural, surface morphology and magneto-transport properties of as grown Eu 0.1 Bi 1.9 Se 3 single crystals.

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Preparation of Cobalt doped Bi2Se3 nano-topological insulators

Cited by 4 publications

References 16 publications

Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Precise Regulation of Carrier Concentration in Thermoelectric BiSbTe Alloys via Magnetic Doping

Structural, surface morphology and magneto-transport properties of self flux grown Eu doped Bi₂Se₃ single crystal

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Preparation of Cobalt doped Bi2Se3 nano-topological insulators

Cited by 4 publications

References 16 publications

Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Growth, Characterization and High-Field Magneto-Conductivity of Co0.1Bi2Se3 Topological Insulator

Precise Regulation of Carrier Concentration in Thermoelectric BiSbTe Alloys via Magnetic Doping

Structural, surface morphology and magneto-transport properties of self flux grown Eu doped Bi2Se3 single crystal

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Product

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Structural, surface morphology and magneto-transport properties of self flux grown Eu doped Bi₂Se₃ single crystal