Has a NEGATIVE and SMALL magnetic susceptibility. When a diamagnetic material is placed in a magnetic field, the magnetization vector M is opposite the direction to the applied field μoH... the resulting B field is less than μoH.
Atoms have closed subshells.
ex. organic materials, many polymers; covalent solids Si, Ge... Cu, Ag, Au.
note: they are superconductors below critical temperature.
Has a POSITIVE and SMALL magnetic susceptibility. Molecules and atoms have random dipole moments in absence of a field.
ex. Alkali and transition metals
Has LARGE, PERMANENT magnetizations even without an applied magnetic field. Magnetic susceptibility is positive and very large (even infinite). Origin is explained by exchange interaction
ex. Some transition and rare earth metals:
Fe, Co, Ni, Gd, Dy
note: occurs BELOW Curie temperature Tc. Above Tc, it is paramagnetic.
Has a SMALL but POSITIVE susceptibility. Has no magnetization without and applied field (and is therefore ANTI-ferromagnetic).
ex. mainly salts and oxides of transition metals... MnO, NiO, MnF2, Cr, Mn
note: occurs BELOW the Neel temperature, T_N. Above T_N, it is paramagnetic
Has similar behavior to ferromagnets BELOW the Curie temperature Tc. Above Tc, they are paramagnetic. The material can possess magnetization even in absence of an applied field. Typically non conducting... used in a lot of high frequency electronics.