# Is the Graph of Lattice Spacing vs Inverse Square Root of Voltage Linear?

• Mathos
In summary, the conversation discusses the parameters for a linear graph in an experiment using a diffraction tube to verify deBroglie's hypothesis. The goal is to find the correct lattice spacings in graphite for d(10) and d(11). The equations used are lambda=1.23/sqrtVoltage, sin4(theta)=Diameter/Length to screen, and Bragg equation: nlambda=2dsin. The speaker suggests plotting d vs 1/sqrtV to obtain a linear graph and mentions the possibility of accounting for electrode work function in the value of V. They also suggest using "D" instead of "d" for the diameter of the diffraction rings.
Mathos

## Homework Statement

I'm just making sure I have the correct parameters for a linear graph. The experiment used a diffraction tube to verify deBroglie's hypothesis. The goal is to find the correct lattice spacings in graphite for d(10) and d(11). This might be lacking in pertinent information, but I imagine this experiment is pretty widely done.

## Homework Equations

lambda=1.23/sqrtVoltage

sin4(theta)=Diameter/Length to screen

Bragg equation: nlambda=2dsin

## The Attempt at a Solution

I think if you plot d vs 1/sqrtV you'll get a linear graph, or at least I thought that. I know this is relatively easy, but I feel like I've just missed something important.

Can you post your graph (preferably using a site like photobucket.com or imageshack.com)?

What you expect seems right, but seeing the graph would help.

Another question, what range of voltages are you using? It may be necessary to account for the electrode work function in the value of V.

p.s.
Since "d" refers to the lattice spacing, can we use "D" for the diameter of the diffraction rings?

p.p.s.
For other potential helpers, here is info on electron diffraction tubes:
http://www.telatomic.com/tubes/diffraction_tube.html

Last edited:

## 1. What is electron diffraction and how does it work?

Electron diffraction is a process in which electrons are scattered off of a sample, producing a diffraction pattern. This is similar to how light is diffracted through a prism. The electrons are accelerated through a high voltage and then directed towards the sample, where they interact with the atoms in the sample and produce a diffraction pattern.

## 2. What are the benefits of using electron diffraction in a lab setting?

Electron diffraction is a powerful tool for studying the structure of materials at the atomic level. It allows for the determination of crystal structures, identification of unknown substances, and analysis of the arrangement of atoms in a material. It also has the advantage of being able to study materials that are not suitable for traditional X-ray diffraction techniques.

## 3. What types of samples can be analyzed using electron diffraction?

Electron diffraction can be used to analyze a wide range of materials, including metals, ceramics, polymers, and biological samples. It is particularly useful for studying materials with a crystalline structure, but can also be used to analyze amorphous materials.

## 4. How is the diffraction pattern interpreted?

The diffraction pattern produced by electron diffraction is a result of the interference of electrons scattered from the sample. The pattern consists of a series of rings or arcs, and the spacing and intensity of these features can be used to determine the crystal structure and orientation of the sample.

## 5. What are some potential sources of error in electron diffraction experiments?

Some potential sources of error in electron diffraction experiments include sample preparation, instrument calibration, and environmental factors such as temperature and humidity. Additionally, the intensity and position of the diffraction pattern can be affected by factors such as sample thickness, crystal defects, and beam energy.

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