  Domain wall motion in magnetic materiel induces the negative susceptibility
leading to a perfect diamagnetism state. The local susceptibility is calculated
by the derivative of magnetization ($\vec{M}$) vector w.r.t. magnetic field
strength ($\vec{H}$) vector. In the transient region from the upward domain to
the downward domain (domain wall width), local $\vec{M}$ and $\vec{H}$ vectors
exhibit opposite slopes, which leads to a negative susceptibility value. A
negative susceptibility value induces the diamagnetism effect leading to a
relative permeability value $<$ 1 $\left(\mu _r < 1\right)$. This diamagnetism
sate originates due to the domain wall motion, which is an entirely different
mechanism from the electron motion's induced diamagnetism. Furthermore, the
strength of the diamagnetism state can be enhanced by tuning the gradient
energy of a domain that may correspond to a perfect diamagnetism state
$\left(\chi _v \approx -1 \Rightarrow \mu _r \rightarrow 0\right)$. Besides, we
believe that there may be a possibility of sustaining such a diamagnetic state
(domain wall induced) in a ferromagnetic material that is utterly contradictory
to the conventional theory.
