180o domain wall between two domains is known as Bloch wall. The Bloch wall energy is competition between exchange energy and anisotropy energy within the interface of two domains. The exchange energy in a ferromagnetic material is a minimum only when adjacent spins are parallel. While anisotropy energy will be minimum when the spins remain parallel to the easy axis.

Bloch wall energy will be minimum of exchange energy and anisotropy energy

Mathematically, the Bloch wall energy for an uniaxial anisotropic material will be

(sigma)exch+(sigma)anis=(JS2 pi2)/Na2+KuNa

where J is exchange stiffness, N is number of atoms within the wall, a is distance between two adjacent atoms, Ku is the uniaxial anisotropy constant

the minimum of this energy terms will be

(sigma)dw~2pi(AKu)1/2

where A is the exchange stiffness constant. it is the energy of the Bloch wall in uniaxial ferromagnetic material. (read more in Cullity's Book)

Wikipedia has an excellent article related to anisotropy that is written for non-specialists. For more information, one would have to decide which application of anisotropy they were interested in and find scientific articles based on their specialty.

Nienchtze Teng has written:

'Exchange bias anisotropy' -- subject- s -: Anisotropy, Spin exchange, Ferromagnetic resonance

abc

Condition in which properties depend on direction (ie, properties are different in different directions)