Carrier type induced magnetoresistance upending in assembly of sulfur doped Sb2Se3 nanotubes

Materials showing low field induced switch over in magnetoresistance is investigated heavily nowadays for promising power electronics and phase change memory applications. In this work, morphological, topographical, magnetoresistance (MR) and thermoelectric properties of nanobulk assembly of sulfur doped Sb2Se3nanotubes synthesized by novel microwave assisted solvothermal process is investigated and reported. Structural properties indicate that the sample crystallizes in orthorhombic phase while morphology study confirms the formation of nanotubes of length 1-5 mu m and diameter 100-150 nm. Electrical resistivity measurements indicates 2D variable range hopping at low temperature (2-50 K), nearest neighbor hopping at intermediate temperature (50-200 K) and thermal activation behavior with activation energy of 2.3 meV from 200 K to 300 K. Interestingly the positive magnetoresistance observed in low magnetic field and at constant low temperatures makes a transition to negative magnetoresistance above 20 K. Bipolaron model along with wave function shrinkage models were invoked to understand the MR measurements while low temperature thermoelectric measurement univocally elucidates that the carrier type switching at 13 K dictates the conduction mechanism as demonstrated by the complex crossover in magnetoresistance.

Automated summary

The study investigates the morphological, topographical, magnetoresistance, and thermoelectric properties of sulfur-doped Sb2Se3 nanotubes synthesized by a novel microwave-assisted solvothermal process. The sample crystallizes in an orthorhombic phase with nanotubes of length 1-5 μm and diameter 100-150 nm. Electrical resistivity measurements indicate different conduction mechanisms at different temperatures, with a transition to negative magnetoresistance observed above 20 K.