Nanotechnology Undergraduate
Education (NUE) - NSF
Introduction to Nanotechnology Undergraduate Education (NUE) NSF
David W. Stollberg, Ph.D., P.E.
EOSL
5 Jun 2011
GTRI_B-1
GTRI_B-2
Primary Bonds
• Ionic
• Charge transfer
• From the extremes of the periodic chart, i.e.,Groups IA
and VIIA(NaCl ),large difference in electronegativity,
boundary approximately 1.7, see Appendix B.
• Covalent
• Sharing electrons in an attempt to make a complete
shell, Group IV elements (C, Si, Ge) and diatomic
elements such as H2, Cl2, and F2.
• Metallic
• Shared by all the atoms in the substance.
GTRI_B-3
Increasing atomic radius
6
C
14
Si
32
Ge
Alkaline earth
metals
Alkali metals
Increasing electronegativity,
increased tendency to add electrons
GTRI_B-4
Noble
gases
Halogens
sp3 hybridized orbitals
Mechanical Rotary Vane Pump
http://www.repairfaq.org/sam/vacuum/rvpnotes.htm
GTRI_B-5
Mechanical Rotary Piston Pump
GTRI_B-6
Diffusion Pump
GTRI_B-7
Turbomolecular
GTRI_B-8
Cryopump
GTRI_B-9
Ion Pump
GTRI_B-10
Equipment
•
http://eosl.gtri.gatech.edu/Capabilities/tabid/508/Default.aspxhttp://eosl.gtri.gatech.edu/Capabilitie
s/tabid/508/Default.aspx
•
http://grover.mirc.gatech.edu/equipment/
•
http://www.youtube.com/watch?v=9p2wwOTpCCI
•
(ALD)
GTRI_B-11
rNa = 0.186nm
Na+
Cl
rCl = 0.107nm
Electron affinity
Na
Ionization potential
Primary Bonds
Cl-
r+Na = 0.098nm
rCl- = 0.181nm
Energy required: 5.14 eV
Energy released: 4.02 eV
GTRI_B-12
Primary Bonds
Fe
Fe2+
Fe3+
r = 0.124nm
r = 0.087nm
r = 0.067nm
Schematic showing the relative size of the electron
clouds of iron and two common valence states
GTRI_B-13
Relative Sizes of Atoms and Ions
Atom
Anion
ratom < ranion
Atom
Cation
ratom > rcation
Neutral atoms are shown in green, cations are red, and anions are blue. Note the
relative change when a neutral atom becomes a cation, compared to an anion.
GTRI_B-14