Register to reply

What happens when we rotate crystal while shooting electrons at it?

by 71GA
Tags: crystal, electrons, rotate, shooting
Share this thread:
71GA
#1
Jul26-13, 05:22 PM
P: 205
I know that if we shoot narrow beam of electrons at the crystal (we don't change the angle) we will get a diffraction of electrons according to the brag's law. Therefore we get minimums and maximums on the screen around the crystal.

Until now we have been dealing with problems where ##\vartheta## (this is an angle between an incoming beam and crystal planes) was constant. It meant that crystal wasn't rotating. To find maximums and minimums we have instead been rotating a sensor around the crystal.

But what would happen if we rotated the crystal? This would mean that we are changing the angle ##\vartheta##! Would minimums and maximums move around the screen or would they only appear and disappear? What is different than before?

A good picture is worth 1000 words.
Phys.Org News Partner Physics news on Phys.org
A new, tunable device for spintronics
Researchers study gallium to design adjustable electronic components
Gadolinium-based material that can be cooled by varying magnetic field
Simon Bridge
#2
Jul27-13, 01:55 AM
Homework
Sci Advisor
HW Helper
Thanks
Simon Bridge's Avatar
P: 12,873
You can probably work it out just by figuring the conditions for diffraction ... start with the standard youngs interference experiment and see what happens when you rotate the plane bearing the slits.

In electron diffraction experiments, the crystal is usually thin in one direction and thick in the other two - so you get extra effects from the geometry.
71GA
#3
Jul27-13, 02:20 AM
P: 205
This problem i am dealing is in fact quite large and speciffic so i have written it in a homework & coursework section here: http://www.physicsforums.com/showthr...20#post4455920


Register to reply

Related Discussions
Electron capture vs internal conversion electrons vs auger electrons High Energy, Nuclear, Particle Physics 1
Which force seperates the electrons and nucleus and causes the electrons to orbit? General Physics 14
Single crystal and poly crystal metal Materials & Chemical Engineering 8
Elementary crystal cell or the whole crystal? Atomic, Solid State, Comp. Physics 1
Number of electrons leaving crystal surface. any help ? Introductory Physics Homework 5