Post-Fabrication Engineering of Metal Nanoparticle Grain Structure and Faceting
Typ
Examensarbete för masterexamen
Program
Nanotechnology (MPNAT), MSc
Publicerad
2019
Författare
Berg, Joel
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
In this thesis metallic nanoparticles of varying size and material are annealed in different
temperatures for varying durations of time in order to observe how each parameter may
affect the number of crystal grains in the particles. The knowledge of how different parameters
affect the number of grains was then used to make single crystal particles and
enhance their faceting using chemical methods. This study indicates an exponential decay
in the number of crystal grains per particle as the annealing temperature is increased, with
both palladium and gold particles becoming nearly single crystal when the temperature
reached 0.7 of the bulk metals melting temperature. The number of crystal grains in a
metal particle have also shown a linear relation to the diameter of the fabricated metal
disks in the size range 100 nm-270 nm. A linear relation could be observed even when
using different annealing methods and for different metals. In an attempt to enhance the
faceting of the metal particles using chemical methods, nanolithography-fabricated palladium
particles could be shaped into cubes, and copper disks could be grown in to larger
Wulff-shaped crystals.
Beskrivning
Ämne/nyckelord
annealing , grain growth , dewetting , solid state dewetting , nanoparticles , gold , palladium , copper