Question

Compare and contrast scanning tunneling microscopy (STM) and atomic force microscopy (AFM)? List at least two advantages and two disadvantages for both methods. Please reference at least one source in your discussion.

Answer 1

1. AFM captures precise images by moving a nanometer sized tip across the surface of the image. The STM captures images using quantum tunneling.

2. The probe makes a direct contact with the surface or calculates the incipient chemical bonding in AFM. The STM images indirectly by calculating the quantum degree tunneling between he probe and sample.

3. The tip in AFM touches the surface gently touches the surface whereas in STM, the tip is kept at a short distance from the surface.

4. AFM resolution is better than the STM. This is why AFM is widely used in nano-technology.

5. When Scanning Tunneling Microscope is normally applicable to conductors, the Atomic Force Microscope is applicable to both conductors and insulators.

6. The AFM suits well with liquid and gas environments whereas STM operates only in high vacuum.

7. Of the two microscopes, the Scanning Tunneling Microscope was the first to be developed.