^Comparative study of Dia, para & ferro
^Comparative study of Dia, para & ferro
| Property | Diamagnetic | Paramagnetic | Ferromagnetic |
| Physical state | Solid, liquid or gas | Solid, liquid or gas | Crystalline solids only |
| Atomic dipole moments | Zero permanent dipole moment | Non – zero permanent dipole moments but oriented randomly | Non – zero permanent dipole moments but organised in domains |
| Effect of external mag. field | Feebly repelled | Feebly attracted | Strongly attracted |
| A freely suspended rod in a uniform magnetic field | A diamagnetic rod aligns itself normal to field | A paramagnetic rod aligns itself along field | A ferromag. rod quickly aligns itself along field |
| In a non uniform magnetic field | Tend to move slowly from stronger to weaker field. | Tend to move slowly from weaker to stronger field | Tend to move quickly from weaker to stronger. |
Intensity of magnetization  |
Small – ve | Small +ve | Large +ve |
| Relative permeability (μr) | 0 ≤ μr < 1 (slightly) | μr > 1 (slightly) | > 1 Quite large
( ≈ 1012) |
Permeability  |
μ < μ0 | μ > μ0 | μ >>μ0 |
Mag. susceptibility  |
Small – ve (≈ 1) | Small + ve (≈ 1) | Large + ve ( ≈ 1012) |
| B in a medium is | More than in diamagnetic | Less than in a paramagnetic | Much lesser in a ferromagnetic |
| Dependence of χm on H | Independent | Independent | Independent |
| Dependence of χm on H | χ ∝ T0 |  (Curie law) |
 (Curie weiss) |
| Can be explained by | Orbital motion of electrons | Spin motion of e– s (90%) | Domain Theory |
| Transition | No | Para increases (on cooling) | Ferro® para (on heating) |
| Effect of temperature | No effect
(Except Bi at low T) |
Decreases | Decreases
(T=TC, F → P) |
| Examples | People, frogs, bismuth, copper, gold, zinc, silver, Diamond, graphite, mercury, lead, water, hydrogen, nitrogen (at NTP),NaCl, CO2, benzene & all inert gases. | Transition elements, rare earth elements and actinide elements, oxygen gas, air, aluminum, tungsten, titanium, cerium. | Iron, cobalt, nickel, gadolinium, dysprosium, Fe2 O3, alnico and alloys containing these elements. |
