Crystal Growth and Magneto-transport of Bi2Se3 Single crystals

TL;DR

This study reports the growth, structural characterization, and magneto-transport properties of Bi2Se3 single crystals, revealing high magneto-resistance, quantum oscillations, and metallic conduction down to 2K, advancing understanding of topological insulator behavior.

Contribution

It presents a detailed synthesis and analysis of Bi2Se3 single crystals with comprehensive transport measurements, including magneto-resistance and quantum oscillations, which are novel for this material.

Findings

Crystals grown by self flux method show rhombohedral structure.

Large positive magneto-resistance observed up to 240% at 14 Tesla.

Quantum oscillations (SdH) detected at 2K under high magnetic fields.

Abstract

In this letter, we report growth and characterization of bulk Bi2Se3 single crystals. The studied Bi2Se3 crystals are grown by self flux method through solid state reaction from high temperature (950C) melt of constituent elements and slow cooling (2C/hour). The resultant crystals are shiny and grown in [00l] direction, as evidenced from surface XRD. Detailed Reitveld analysis of PXRD (powder x-ray diffraction) of the crystals showed that these are crystallized in rhombohedral crystal structure with space group of R3m (D5) and the lattice parameters are a = 4.14(2)A, b = 4.14 (2) A and c = 28.7010(7) A. Temperature versus resistivity (R-T) plots revealed metallic conduction down to 2K, with typical room temperature resistivity (R300K) of around 0.53 mohm-cm and residual resistivity of 0.12 mohm-cm. Resistivity under magnetic field ] measurements exhibited large +Ve magneto resistance right from 2K to 200K. Isothermal magneto resistance [RH] measurements at 2K, 100K and 200K exhibited magneto resistance (MR) of up to 240, 130 and 60 percent respectively at 14 Tesla. Further the MR plots are non saturating and linear with field at all temperature. At 2K the MR plots showed clear quantum oscillations at above say 10 Tesla applied field. Also the Kohler plots i.e., were seen consolidating on one plot. Interestingly, the studied Bi2Se3 single crystal exhibited the Shubnikov-de Haas oscillations (SdH) at 2K under different applied magnetic fields ranging from 4Tesla to 14 Tesla