Here's why:
* Electromagnetic lenses: Instead of glass lenses, electron microscopes use electromagnetic lenses. These lenses are essentially coils of wire that create magnetic fields.
* Focusing the beam: The magnetic field created by the coils bends the path of the electrons, focusing them into a fine beam.
* Controlling the beam: These magnetic lenses can be adjusted to change the focus, magnification, and direction of the electron beam.
There are two main types of electron microscopes, both using magnets:
* Transmission electron microscope (TEM): Uses a beam of electrons that pass through the sample, forming an image from the transmitted electrons.
* Scanning electron microscope (SEM): Uses a focused beam of electrons that scan the surface of the sample, producing images based on the interaction of the electrons with the sample.
The magnetic fields in electron microscopes play a crucial role in achieving the high resolution and magnification capabilities that these instruments are known for.
