| A paramagnetic material | A ferromagnetic material |
| 1. The permanent atomic magnetic moments of a para‐ magnetic material are all randomly oriented so that, in the absence of an external magnetizing field, the material is unmagnetized. | 1. The permanent atomic magnetic moments of a ferro‐ magnetic material interact strongly through exchange interaction forming domains which are spontaneously magnetized to saturation |
| 2. It gets weakly magnetized when placed in an external magnetic field. | 2. In an unmagnetized ma‐ terial, the directions of magnetization of the different domains are so oriented that the net magnetization is zero. |
| 3. Its magnetization becomes zero when the external magnetic field is removed. | 3. It retains some magnetization even after the external magnetic field is removed. |
| 4. Its magnetization in a given external magnetic field increases with decreasing temperature. The magnetization reaches saturation only if the external field is very large and the temperature is very low. | 4. It retains its domain structure only up to a characteristic Curie temperature, above which it becomes paramagnetic. |
| 5. χm is small and positive. μr is slightly greater than 1. | 5. χm and μr are positive and very high. |
