we know,

susceptibility = intensity of magnetization (I) / Magnetizing intensity (H)

permeability = 1 + susceptibility

for a perfectly diamagnetic substance,

intensity of magnetization (I) = -Magnetizing intensity (H)

negative sign shows that the opposite alignment of electrons against the direction of applied magnetic field.

thus, susceptibility = -1 ( acts as super conductor )

and, permeability =0 ( no magnetic lines of force pass through the material )

Permeability can also be understood by...

Lagging of magnetic field behind the magnetizing field in a ferromagnetic material taken through a cycle of magnetization is called the hysteresis.

From the hysteresis loop, a number of primary magnetic properties of a material can be determined.

Retentively- A measure of the residual flux density corresponding to the saturation induction of a magnetic material. In other words, it is a material's ability to retain a certain amount of residual magnetic field when the magnetizing force is removed...