- Nanotechnology is the manipulation of matter on the nanometer scale, which is 1 to 100 nanometers. - At the nanoscale, the properties of materials can change dramatically and differ from the properties of macroscale materials. For example, metals can become stronger or change from opaque to transparent. - The properties change due to increased surface area to volume ratio at the nanoscale and quantum effects dominating behavior. The increased surface area affects chemical reactivity, while quantum effects influence bandgap and magnetic properties. - Controlling materials at the nanoscale allows for designing new materials and systems with applications across many industries like optics, electronics, and biomedicine.

1. 7TH SEMESTER
26 –FBAS/BSPHY/F-10
BS-PHYSICS(NANOTECHNOLOGY)
INTERNATIONAL ISLAMIC UNIVERSITY ISLAMABAD

2. PHYSICS AT NANOSCALE
PRESENTATION “INTRODUCTION TO
NANOTECHNOLOGY”

3. NANOTECHNOLOGY

4. NANOTECHNOLOGY???

5. Nanotechnology is the creation of the functional materials
,devices and systems through control of the matter on the
nanometer scale and the exploitation of the novel
phenomenon properties at that length scale .
(NASA)

6. NANOTECHNOLOGY is:
 Creation of useful materials, devices, and
systems through the manipulation of matter
on nanometer scale.

7. NANOMETERSCALE
(1 -100)nm

8. NANOMETER…..???

9. 10-9
m

10. NANOMETER:
 ONE BILLIONTH PART OF A METER IS CALLED
NANOMETER.
 THE LENGTH EQUIVALENT TO TEN HYDROGEN
OR FIVE SILICON ATOMS ALLIGN IN A STRAIGHT
LINE.

11. SIZE
A meter is about the distance from the tip of your nose to the end
of your hand (1 meter = 3.28 feet).
Millimeter- One thousandth of meter.(10-3m)
Micron: a micron is a millionth of a meter (or) one thousandth of
millimeter (10-6m)
Nanometer:
A nanometer is one thousandth of a micron (10–9m)
(or) a billionth of a meter. ie.,one billion nanometers in a meter.

12. NANOTECHNOLOGY
 - Generally nanotechnology deals with structures sized
between 1 to 100 nanometer in at least one dimension.
 Ability to design systems with defined structure and
function on the nanometer scale.
 Involves developing materials, devices within that
size

13. NANOTECHNOLOGY CONT…
Interdisciplinary area :
Biology, Physics, Chemistry, Material
science, Electronics,
Chemical Engineering, Information
technology

14. NANOTECHNOLOGY
→ Nanotechnology is science, engineering, and
technology conducted at the nanoscale, which is
about 1 to 100 nanometers..
→ Nanoscience and nanotechnology are the study
and application of extremely small things and can be
used across all the other science fields, such as
chemistry, biology, Physics.

15. Nanotechnology Plays by Different Rules
Normal scale Nanoscale

16. Evolution of Technologies
Pico/Femto
Technology
3000

17. NANOMATERIAL:
 A material which has at least one dimension in
the range of (1-100)nm is called nanomaterial.

20. Nanoscale materials are divided into three category,
1. Zero dimension – length , breadth and heights are confined at
single point. (for example, Nano dots)
2. One dimension – It has only one parameter either length (or)
breadth (or) height ( example: very thin surface coatings)
3. Two dimensions- it has only length and breadth (for example,
nanowires and nanotubes)
4. Three dimensions -it has all parameter of length, breadth and
height. (for example, Nano Particles).
A material which has at least one dimension in the range of (1-100)nm is called
nanomaterial.
NANOMATERIAL:

21. Quantum well
• It is a two dimensional system
• The electron can move in two directions and restricted in one direction.
Quantum Wire
• It is a one-dimensional system
• The electron can move in one direction and restricted in two directions.
Quantum dot
• It is a zero dimensional system
• The electron movement was restricted in entire three dimensions

22. Why called Quantum ?
• Because, the electronic property is
quantized
• The spatial distance is very very small

23. substrateSemiconductor
growth (single
layer)

26. • Nanoparticles
• Nanocapsules
• Nanofibers
• Nanowires
• Fullerenes (carbon 60)
• Nanotubes
• Nanosprings
• Nanobelts
• Quantum dots
• Nanofluidies
Based on the size and shape, the Nano materials are classified as follows

27. In quantum dot all the three dimensions are reduced to zero
Quantum dot

28. Dimension Variation 

29. • Cu - Opaque
• Pt, Au - Inert
• Al - Stable
• Au - Solid
• Si - Insulator
Materials at Micro scale

30. Materials at Nano scale
• Cu - Opaque → Transparent
• Pt, Au - Inert → Catalysts
• Al - Stable → Combustible
• Au - Solid → Liquid
• Si - Insulator → Conductor

31. • Composites made from particles of nano-size ceramics or metals smaller than 100
nanometers can suddenly become much stronger than predicted by existing
materials-science models.
• For example, metals with a so-called grain size of around 10 nanometers are as
much as seven times harder and tougher than their ordinary counterparts with
grain sizes in the micro meter range.
• The Nano particles affects many properties such as
Melting point
Boiling point
Band gap
Optical properties
Electrical properties
Magnetic properties
• .Even the structure of materials changes with respect to Size

32. Why Nano changes the
properties of materials?

33. The properties of materials can be different at the Nanoscale for two main reasons:
First, Nanomaterials have a relatively larger surface area when compared to the same
mass of material produced in a larger form.
Nano particles can make materials more chemically reactive and affect their strength or
electrical properties.
Second, quantum effects can begin to dominate the behaviour of matter at the Nanoscale

34. WHY NANO WILL CHANGE THE PROPERTIES OF
MATERIALS?
AT THE NANO SCALE THE PROPERTIES
CHANGES DUE TO INCREASE IN
SURFACE TO VOLUME RATIO.

35. Why Nano will change the properties of
materials?
Smaller size means larger surface area
0.5 1 2 3 4
1
2
3
4
5
6
R
S / V
0
7
8
9
10
11
12
5
R
Sphere
• Volume, V = 4/3 π R3
• Surface Area, S = 4πR2
• Ratio S/V = 3 /R
For He atom, 2R = 0.1 nm. S/V = 6 × 1010
R S/V
3 1
2 1.5
1 3
0.5 6
0.25 12
0.125 24

37. The melting point decreases dramatically as the particle size gets below 5 nm
Source: Nanoscale Materials in Chemistry, Wiley, 2001
Melting Point

38. Band gap
The band gap is increases with reducing the size of the particles

39. Surface Area
The total surface area (or) the number of surface atom increases with reducing size of
the particles

40. • For semiconductors such as ZnO, CdS, and Si, the bandgap changes
with size
- Bandgap is the energy needed to promote an electron
from the valence band to the conduction band
- When the bandgaps lie in the visible spectrum, changing
bandgap with size means a change in color
• For magnetic materials such as Fe, Co, Ni, Fe3O4, etc., magnetic properties are size
dependent
- The ‘coercive force’ (or magnetic memory) needed to
reverse an internal magnetic field within the particle is
size dependent
- The strength of a particle’s internal magnetic field can be
size dependent

42. 07-FBAS/BSPHY/F-10

43. MECHANICAL PROPERTIES

44. MECHANICAL PROPERTIES
 Mechanical properties of nanomaterials may reach the
theoretical strength, which are one or two order of
magnitude higher than that of single crystal in the
bulk form .
 The enhancement in the mechanical strength is simply
due to the reduced probability of defects.

45. OPTICAL PROPERTIES

46. OPTICAL PROPERTIES
 In the classical sense, colour is caused by the optical
absorbtion of light by the electron in matter, resulting
in the visibility of the complementary part of the light.
 On the smooth metal surface, light is totally reflected
by the high density of electron, no colour , this is a size
dependent property.

47. MAGNETIC PROPERTY

48. MAGNETIC PROPERTY
 Magnetic properties of nano structured materials are
distinctly different from that of bulk materials e.g the
coercive force or the magnetic memory needed to
reverse an internal magnetic field changes with the
changes in the size.
 The internal magnetic field is also size dependent.
 Ferromagnetism disappears and transfers to
superparamagnetism in the nanometer scale range
due to huge surface energy.

49. WELCOME TO QAZI MAAZ US SALAM