Nanoscience 15 lectures + 3 tutorials Dr Pete Nellist (coordinator) 13 lectures + 2 tutorials 4007...
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Transcript of Nanoscience 15 lectures + 3 tutorials Dr Pete Nellist (coordinator) 13 lectures + 2 tutorials 4007...
Nanoscience15 lectures + 3 tutorials
Dr Pete Nellist (coordinator)13 lectures + 2 tutorials
4007 SS Physics
Prof Suzi Jarvis Biological nanomaterials1 lecture
Prof John Boland Mechanical properties1 lecture
Books:•Introduction to Nanotechnology, Poole and Owens (Wiley)•Quantum Mechanics, McMurry•Quantum Semiconductor Structures, Weisbuch and Vintner (AP)
Timetable (subject to change)Lectures are at:
Tuesdays 5 pm in the Schroedinger Lecture Theatre.
Wednesdays 4 pm in the SNIAM Physics Lecture Theatre.
Date Lecturer25 January No lecture
All tutorials will be in the Trinity term.
Nellist Lectures
• Combination of figures on Powerpoint and handwritten notes.– Copies of handwritten notes will not be provided, so keep notes
during the lectures.
• Powerpoint presentations can be found at:
http://www.tcd.ie/Physics/People/Pete.Nellist/
Why nanoscience?
• Nanoscience (nanotechnology) is usually defined as being based on structures 1-100nm in dimension.– Typical interatomic spacing ~0.2nm, so can consist of a few tens
to hundreds of millions of atoms.
• Feynman talk “There’s plenty of room at the bottom” (www.zyvex.com/nanotech/feynman.html).– He is mainly discussing minaturization– Also can exploit quantum effects.
Moore’s law
Gordon Moore
1929-
• Moore’s law: The number of transistors on a chip doubles every two years.– Transistor dimensions are now as small as 65 nm, so this is
nanotechnology rather than microtechnology.
Single atoms
• These are Fe atoms positioned on a Cu surface.– They were positioned
using a scanning tunnelling microscope (STM).
– Don Eigler at IBM.
Metal nanoparticles
2 nm2 nm
2 nm
Metal nanoparticles and single atoms
1 monolayer (single atom and raft)
A B C
D
C
D
0
2 monolayers
Au cryst.
a b c d
1.0 Å
1.4 Å
10 Å
Multiply twinned particles
• Often nanoparticles are multiply twinned.– This is done to minimise the surface energy.
Catalysts
At the nanoscale, physics and chemistry converge
The Lycurgus Cup
• The Lycurgus Cup is unusual in that the reflected light colour (green) is different to the colour of transmitted light (red).
• The reason is that the glass contains 70 nm diameter nanoparticles of gold.– Nanoparticles of gold can appear to have different colours depending on
their size.
Buckminsterfullerene
• A carbon-60 molecule.– C60 is also known as Buckminsterfullerene (buckyballs).
– Other similar molecules (such as C70) exist.
• When doped with alkali metals, the resulting structure can act as a superconductor.
Carbon nanotubes• Discovered by Sumio
Iijima in 1991.– S. Iijima, Nature 354
(1991) 56.
• They can be metallic or semiconducting.
• They are mechanically extremely strong.– Use for composites?
Inorganic nanowire ropes
• These are ropes about 10 nm in diameter.
• They are made from individual chain molecules of Mo6S4.5I4.5.– The individual chains can
be seen in the image.
• These ropes are thought to have metallic properties.
Quantum Dots
• Show zero-dimensional quantum effects.
• Many optical applications– quantum lasers– light emitting diodes– single electron transistors
Quantum wells
• Also optically important– For example infra-red detectors
• Can also have quantum wires
Biological Macromolecules
Five Bakers Dancing!
DNA
Dioxy Ribonucleic Acid
Is sometime made synthetically for use as a nanostructure.
Spintronics
Hard disk read/write head.