1. The document summarizes the Davisson-Germer experiment, which was the first to demonstrate the wave nature of electrons. 2. The experiment involved firing a beam of electrons at a nickel crystal and observing the diffraction pattern of the electrons emerging from the crystal. 3. This provided direct evidence that electrons behave as waves, with a wavelength given by the de Broglie relationship, thus validating the de Broglie hypothesis about the wave-particle duality of matter.

1. Presented By :
Uzair Aziz (70059225)
Presented To :
Mam Ayesha Abbas
Program :
Bs-Physics (Sem-V)
Topic :
Wave nature of matter , DAVISSON
and GERMER Experiment

2. CONTENTS
• WAVE NATURE OF PARTICLE
1. Definition
2. DE BROGLIE HYPOTHESIS
• DAVISSOINANDGERMEREXPERIMENT
1. Introduction
2. Definition
3. Apparatus
4. Working
5. Derivation
6. Conclusion

3. WAVE NATURE OF MATTER
• Light has dual nature
• The scientist Louis de Broglie put forward a theory( De BROGLIE HYPOTHESIS)
• Nature loves symmetry
• If radiation has two natures than matter should have two nature
• Material nature
• Wave nature

4. • For example: If we through a ball it should travel
1. In straight line
2. Spread like wave
3. Both
• Hypothesis Says:A material when it is moving ,sometime act like.
1. Matter
2. Wave
• When a matter move, it is always guided by wave which is surrounded it.
• Surrounded by which wave?
• That wave is called Matter wave.
A wave which accompanies moving a matter.
• It’s third type of wave

5. • It’s a material wave that guide the motion of a matter.
• Every moving particle is surrounded by a wave .
• Its position and momentum are uncertain.
• Its given by the uncertainty principle.
• The behaviour of this particle will be in the form of wave.
• It has a particular wavelength ( λ = h/p ).
Conclusion:
• Any object we through with a certain velocity has mass.
• It will go with the form of wave .

6. DAVISSOIN AND GERMER EXPERIMENT
• The 1st Experiment proof of the De Broglie hypothesis
• It was done by two American scientist
• Clinton J. DAVISSOIN and LASTER H. GERMER in 1926
Principle:
• The electron beams get diffracted when scattered by a crystal.In this experiment,
electrons emerge out of a hole in the form of a fine beam which is then made to fall
on a nickel crystal.

7. • Electrons are diffracted from metal crystal in the same way as
x-rays or any other wave.
Apparatus
• Electron gun
• Potential divider
• Nickle crystal
• Moveable Detector

8. o WORKING
• When Filament is heated it emits electrons.
• Electrons are accelerated by adjustable applied voltage(V).
• The beam of accelerated electrons gains K.E(eV0)
• This beam is allowed to fall normally on a Nickel Crystal.(Ni)
• The diffracted beam from crystal surface enters a detector
• Recorded as a current “I”.

9. o DERIVATION
• The gain in K.E of the electron as it is accelerated by a potential V In the electron gun is given b
1⁄2 mv2= Ve
mv2 = 2Ve
m2v2 = 2mVe
mv = √2mVe
According to de Broglie equation
λ = h/mv
λ = h/ √2mVe
If accelerating voltage V = 54V

10. Conclusion :
This experiment prove the electron behave as wave when
travels so de Broglie hypothesis is confirmed . (∆ λ= 0.01)

11. THANK YOU…😊