  This paper presents the hidden magnetization features of ferromagnetic
materials: called miamagnetism. As we know, we have several forms of
magnetization: the diamagnetism, the paramagnetism, the ferromagnetism etc. The
main character of the diamagnetism is that its magnetic susceptibility is
negative (from -1e-9 for gas and -1e-6 for liquid and solid to -1 for
superconducting materials of type I) and it is not less than -1 unless for
special materials like metamaterials at high frequencies. The miamagnetism has
the character that the magnetic susceptibility can reach at low frequencies a
negative value of -155 of magnitude leading to a negative permeability. We can
not see it because it is hidden by the ferromagnetic character which has a high
positive magnetic susceptibility. We use the discrete Fourier transform to
illustrate this hidden character and the hysteresis model can be represented
only by harmonics of (2n+1)f0 of magnitude. This magnetization follows a
Boltzmann distribution for the modulus of theses harmonics.
