Ion tracks technology proved to be a precursor to Nanotechnology; a technique used in our Laboratory for almost 25 years, with collaboration of GSI, Darmstadt, Germany.
TataKelola dan KamSiber Kecerdasan Buatan v022.pdf
Ssntd ion track technology to nanotechnology
1. My Journey from Ion Track
Technology to Nanotechnology
Hardev Singh Virk
Professor Emeritus
Eternal University, Baru Sahib,
HP, India
2. History of Nuclear Tracks
Rutherford’s discovery Alpha tracks:1906
(Wilson Cloud chamber used as a detector)
Ruchi Ram Sahni studied Alpha tracks in
Nuclear Emulsion in Rutherford Lab.1915
Discovery of Pi Mesons by C.F. Powel using
Nuclear Emulsions in Bristol 1940s
Beva Chowdhary used N. Emulsions for
study of Pi mesons in Calcutta University.
D.Lal, Y.Pal & B.Peters in TIFR used NE:1950s
3. Routes to Nanotechnology
• Physical, chemical, biological and nature’s self
assembly.
• Top-down and bottom-up approaches.
• Chemical route to nanotechnology is simpler,
cheaper and allows fabrication at bench top
conditions.
• Reverse micelles (microemulsions route) is a
versatile method to produce a variety of
nanoparticles.
4. My Route to Nanotechnology
• Ion Track Technology Route using Heavy Ion
Beams from GSI, Darmstadt & JINR, Dubna.
• Chemical Route of Reverse micelles, co-
precipitation, solvo-thermal, sol-gel and seed
growth techniques.
• Quantum dots, nanorods and nanoneedles of
Barium Carbonate, Barium Oxalate, Iron Oxalate,
Barium hexaferrite, Zinc Oxide, Cadmium
Sulphide, Cadmium Oxide and Silver prepared.
5. Ion Track Technology
Ion Track Technology [1] was developed at GSI,
Darmstadt. Ion Track Filters (ITFs) or Track-etched
membranes became precursors to development of
nanotechnology during 1990s. ITFs were prepared
by bombardment of thin polymer foils using heavy
ions. One of the first applications of ITFs was
separation of cancer blood cells from normal blood
by making use of Nuclepore filters. Author’s group
used heavy ion beam facility available at GSI
UNILAC, Darmstadt during 1980s for Ion Beam
Modification of Materials and to prepare ITFs in our
laboratory.
[1] R. Spohr: Ion Tracks and Microtechnology: Principles and Applications
(Vieweg Publications, Weisbaden Germany, 1990)
10. Ion Tracks as Structuring Tools
Ion tracks are created when high-energetic heavy
ions with energy of about 1 MeV/nucleon (e.g. 140
MeV Xe ions) pass through matter. The extremely
high local energy deposition along the path leads to
a material transformation within a narrow cylinder of
about 10 nm width. Unlike in the more conventional
lithographic techniques based on ion or electron
beam irradiation, a single heavy ion suffices to
transform the material.
11. Revelation of Ion Tracks
Latent tracks were first observed in Mica by Electron
Microscope with diameter range of 50-100 Angstrom
(5-10nm).
Chemical etching was first used by DA Young in
Harwell (1958) to reveal fission fragment tracks in
LiF and Mica. They can be observed using Optical
Microscope. Ion tracks can be recorded in almost all
Insulators( polymers, glasses, inorganic crystals)
and some Semi-conductors.
15. How to Use Ion Tracks
There are essentially two ways to use ion tracks for
nanostructuring. The first is based on track etching
as used in the filter production, i.e. one irradiates a
polymer foil and etches the tracks to create thin
pores in the foil. These pores are subsequently filled
with an appropriate material to make
nanostructures. In this process, the polymer foil
serves as a template and can be removed
(dissolved) if required.
The second method uses the ion tracks directly
without additional etching and refilling steps. This
method is simpler than the template technique since
no filling of the pores is required, but its scope is
limited.
16. Nanowire Fabrication
Template synthesis using polymer and anodic
alumina membranes
Electrochemical deposition
Ensures fabrication of electrically continuous wires
since it only takes place on conductive surfaces
Applicable to a wide range of materials
High pressure injection
Limited to elements and heterogeneously-melting
compounds with low melting points
Does not ensure continuous wires
Does not work well for diameters < 30-40 nm
Chemical Vapor Deposition (CVD) or VLS technique
Laser assisted techniques
20. Template Synthesis of Copper Nanowires
The concept of electro-deposition of metals through
electroplating is described as an electrochemical
process. The etched pores of ITFs used would act
as a template. The electrolyte used here was
CuSO4.5H2O acidic solution. The rate of deposition
of metallic film depends upon many factors, i.e.,
current density, inter-electrode distance, cell
voltage, electrolyte concentration and temperature
etc. In the present set up electrode distance was
kept 0.5 cm and a current of 0.0025A was applied
for 50 minutes. The developed microstructures
were scanned under SEM (Jeol, JSM-6100) for
morphological and structural studies.
21. AFM image of hexagonal pores of Anodic
Alumina Membrane (AAM)
22. SEM Images of Cu Nanowires using
Electrodeposition Technique