Synthesis, Characterization and Investigation of Electrical Transport in Metal Nanowires and Nanotubes

TL;DR

This thesis explores the synthesis, structural characterization, and electrical transport properties of metal nanowires and nanotubes, revealing how size and shape influence electron interactions and phase transitions.

Contribution

Developed electrochemical deposition methods for single-crystalline metal nanowires and nanotubes, and studied their electrical and magnetic transport properties across temperature ranges.

Findings

Electrical interactions scale with nanostructure dimensions.

Characteristic temperatures vary with nanostructure size and shape.

Transport properties differ between nanowires and nanotubes.

Abstract

This thesis is dedicated to the synthesis, characterization and the study of electrical transport through metal nanowires and nanotubes. The metal nanowires(Ni, Cu) and nanotubes(Cu) are synthesised by electrochemical deposition in nanoporous templates. In the synthesis front, electrochemical deposition schemes were developed to achieve single crystallinity and synthesis of tubular nanostructures. The nanostructures are characterized using structural characterization techniques such as X-ray diffraction, Scanning electron microscopy and Transmission electron microscopy. The magnetic nanowires are also characterized using VSM and SQUID magnetometers. The electrical transport measurements performed in a wide range of temperature (3K-700K) to understand the interactions of electrons with phonon, magnon and surface when the electron mean free path is limited by the dimension of these nanostructures. The measurements were performed in the wide range of temperature to encompass and study the ferromagnetic to paramagnetic phase transition in case of magnetic nanowires. We observed systematic scaling of these interactions and the characteristic temperatures such as the Debye temperature(\theta_R) and Curie temperature(T_C) as a function of diameter. We also observed how these interactions change as we move from nanowires to nanotubes of metals.