Negative Magnetoresistance in Amorphous Indium Oxide Wires

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Amorphous Indium oxide nanowires display complex magneto-transport properties.
• Superconducting transitions are observed, yet finite resistance persists at low temperatures.
• Understanding the factors influencing these properties is crucial for potential applications.

Purpose of the Study:

• To investigate the magneto-transport characteristics of amorphous Indium oxide nanowires with varying widths.
• To elucidate the origin of negative magnetoresistance (nMR) observed in these nanowires.
• To determine the dependence of nMR and crossover fields on temperature and cross-sectional area.

Main Methods:

• Fabrication of amorphous Indium oxide nanowires with controlled widths.
• Measurement of resistance (R) as a function of temperature (T) and applied magnetic field.
• Analysis of R(T) broadening using phase slip models.
• Characterization of negative magnetoresistance (nMR) and its field dependence.

Main Results:

• Superconducting transitions were observed in zero magnetic field, with finite residual resistance at low temperatures.
• The resistance broadening was successfully modeled using phase slip theories.
• Negative magnetoresistance (nMR) was observed in wires with diameters ≤ 100 nm at low fields and temperatures below the critical temperature.
• The magnitude of nMR and the field crossover were found to be dependent on both temperature and the nanowire's cross-sectional area.

Conclusions:

• The observed finite resistance is attributed to phase slip phenomena.
• The intriguing negative magnetoresistance (nMR) behavior arises from the interplay of two distinct field-dependent contributions.
• The findings provide insights into the magneto-transport properties of amorphous oxide nanowires, relevant for nanoscale electronic devices.