Calculating STM Resolution Based on Tip Size

Thread starter MrCaN
Start date Jan 8, 2004
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Resolution Stm

In summary, the scanning tunneling microscope (STM) operates by passing a small, electrically conductive tip close to the sample surface to create a tunneling current. The resolution of an STM image is directly proportional to the size of the tip used, with a smaller tip resulting in higher resolution. The formula for calculating STM resolution takes into account tip size, tunneling current, and the slope of the current vs. distance curve. While using a smaller tip can improve resolution, there is a limit before it becomes unstable. Other factors such as instrument stability and sample cleanliness also affect STM resolution.

Jan 8, 2004

MrCaN

does anyone have a link or a formula for calculating the resolution of a STM based on the tip size.

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Jan 13, 2004

LURCH

Science Advisor

According to this link and a couple others, the tip of a STM is a single protruding molecule and, under ideal conditions, can record the possition of individual molecules.

So I geuss the ratio of resolution to tip size is about 1/1.

1. What is the basic principle behind calculating STM resolution?

The scanning tunneling microscope (STM) operates by passing a small, electrically conductive tip very close to the surface of a sample. As the tip moves across the sample, it creates a tunneling current, which is highly dependent on the distance between the tip and the sample. This current can be measured and used to create an image of the surface, with higher resolution achieved by using a smaller tip.

2. How does tip size affect STM resolution?

The resolution of an STM image is directly proportional to the size of the tip used. A smaller tip will create a smaller tunneling current, allowing for more precise measurement of distance between the tip and the sample. This results in a higher resolution image.

3. What is the formula for calculating STM resolution based on tip size?

The formula for calculating STM resolution is: Resolution = (0.5 x Tip Diameter) / (Tunneling Current x Slope of Tunneling Current vs. Distance Curve)

4. Can STM resolution be improved by using a smaller tip?

Yes, STM resolution can be improved by using a smaller tip. However, there is a limit to how small the tip can be before it becomes unstable and difficult to control.

5. Are there any other factors besides tip size that affect STM resolution?

Yes, in addition to tip size, the tunneling current and the slope of the tunneling current vs. distance curve also play a significant role in determining STM resolution. The stability of the instrument and the cleanliness of the sample surface can also impact the resolution achieved.