Magneto-resistive property study of direct and indirect band gap thermoelectric Bi-Sb alloys

Abstract

We report magneto-resistive properties of direct and indirect band gap Bismuth-Antimony (Bi-Sb) alloys. Band gap increases with magnetic field. Large positive magnetoresistance (MR) approaching to 400% is observed. Low field MR experiences quadratic growth and at high field it follows a nearly linear behavior without sign of saturation. Carrier mobility extracted from low field MR data, depicts remarkable high value of around 5 m 2 V −1 s −1 . Correlation between MR and mobility is revealed. We demonstrate that the strong nearly linear MR at high field can be well understood by classical method, co-build by Parish and Littlewood.

Enhancement of electron mobility and thermoelectric power factor of cobalt‐doped n ‐type Bi 2 Te 3

“…The best fit value of m, as extracted by fitting μ-T plot, is provided in Table 1. Similar 'm' values, which is related to the behaviour of phonon scattering, have earlier been reported for polycrystalline Bi, 41 Bi-Sb alloys, 42 and SrTiO 3 . 43 In addition, Figure 6 also depicts that μ substantially increases with Co doping, though for x = 0.05 and 0.1 samples, the obtained values of μ are almost the same.…”

The effect of quenching from different temperatures on Bi0.88Sb0.12 alloy

“…Bi, however when alloyed with semimetal Sb constitutes a continuous solid solution for the entire range of Sb concentration [3][4][5]. The Bi-Sb alloy have received special attention due to their attractive physical properties [3,[6][7][8][9], emerging from peculiarities of its band structure. Electron-electron and electron-phonon scattering plays an important role in transport properties of this alloy and thus influence its thermoelectric properties [10].…”

Noncontact Mutual-Inductance-Based Measurement of an Inhomogeneous Topological Insulating State in Bi2Se3 Single Crystals with Defects

“…To study the effect of disorder on TI, the popular Bi2Se3 crystals are a suitable choice, as they intrinsically possess Se vacancies which are a nature source of disorder in this material. The TI nature of Bi2Se3 has been identified through magneto-transport studies which confirm the presence of conducting surface states through the observation of SdH oscillations and weak anti-localization effects [16,21,22,23,24,25]. In Bi2Se3 the bulk insulating gap has been estimated to be ~ 300 meV [7,10,26,27].…”

“…Without counter doping, the issue of investigating how Se vacancies affects the TI state in Bi2Se3 single crystals is none the less important. Studies show that increasing Se vacancy concentration weakens the SdH oscillations, which is a fingerprint of the conducting surface states characterizing a TI [21][22][23][24]33,34,35,36]. The SdH oscillations in magneto-transport are typically measurable at low temperature and high magnetic field regime.…”