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Paramagnetic materials: atomic moments tend to align with some external magnetic field. The resulting magnetization creates an internal magnetic field that reinforces the externally applied magnetic field.
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Diagmagnetic materials: induced atomic moments tend to align in opposite direction with some external magnetic field. The resulting magnetization creates an internal magnetic field that weakens the externally applied magnetic field.
Inside of these materials, many times we can simply replace $\mu_0$ in our previous equations by
$$ \mu=\mu_{r} \mu_{0} $$ where $\mu$ is the permeability of the material and $\mu_r$ is the relative permeability. We can also define the magnetic susceptibility $$ \chi_m=\mu_r-1 $$| Material | $\chi_m$(T=20º) |
|---|---|
| Platinum | 26 |
| Aluminum | 2.2 |
| Sodium | 0.72 |
| Oxygen gas | 0.19 |
| Bismuth | -16.6 |
| Mercury | - 2.9 |
| Silver | -2.6 |
| Carbon (diamond) | -2.1 |
| Lead | -1.8 |
| Sodium chloride | -1.4 |
| Copper | -1.0 |
#Ferromagnetism
Ferromagnetism: magnetic moments tend to align even if there is no externally applied magnetic field. Their behavior is therefore nonlinear. Magnets are actually ferromagnetic.
https://youtu.be/znQgTv3spnE - Magnetization by friction
Magnetic Force