Energies involved in the domain growth
To study the domain structure clearly, we must know the four type of energy involved in the process of domain growth.
1. Exchange energy
It is the energy associated with the quantum mechanical coupling that aligns the individual atomic dipoles with in a single domain. It arises from interaction of electron spins. It depends upon the interatomic distance.
The excess work done in magnetizing a specimen to saturation in (111) direction compared with (100) direction is about 1.4×104 Joules /m3 .And this is the antistrophic energy of iron .in FCC nickel the reverse is true. For nickel,(111) direction the easy direction of nickel are body diagonals. This energy is very important in determining the character of domain boundary.
Domain wall energy (Bloch wall energy)
It is the sum of contributions from the exchange and crystal line anisotropy energies in the domain wall region .thickness of the wall is approximately 1000A.the boundary between two domains is known as Bloch wall’.
1. Magneto static energy
When a ferromagnetic substance produces an external field, magnetic potential energy, or magneto static energy is present in that material. This is due to the presence of resultant dipole moment n that material even in the absence of external magnetic field this energy is favorable for domain growth if the magnetic moment present in the material is along the direction of magnetization or not.
2. magnetostrictive energy
The change in length along the direction of magnetization of a domain solid refers to magnetostriction .notably we can see this in nickel and ferrites. So if a rod or tube of nickel is brought in to a magnetic field parallel to its length change slightly. The change in length is independent of the sign of field and may be either decrease or an increase depending upon the nature of the material.
Thus the magnetostriction in the domains. This energy will affect the growth of domains.
To study the domain structure clearly, we must know the four type of energy involved in the process of domain growth.
1. Exchange energy
It is the energy associated with the quantum mechanical coupling that aligns the individual atomic dipoles with in a single domain. It arises from interaction of electron spins. It depends upon the interatomic distance.
- Crystal anisotropy energy
The excess work done in magnetizing a specimen to saturation in (111) direction compared with (100) direction is about 1.4×104 Joules /m3 .And this is the antistrophic energy of iron .in FCC nickel the reverse is true. For nickel,(111) direction the easy direction of nickel are body diagonals. This energy is very important in determining the character of domain boundary.
Domain wall energy (Bloch wall energy)
It is the sum of contributions from the exchange and crystal line anisotropy energies in the domain wall region .thickness of the wall is approximately 1000A.the boundary between two domains is known as Bloch wall’.
1. Magneto static energy
When a ferromagnetic substance produces an external field, magnetic potential energy, or magneto static energy is present in that material. This is due to the presence of resultant dipole moment n that material even in the absence of external magnetic field this energy is favorable for domain growth if the magnetic moment present in the material is along the direction of magnetization or not.
2. magnetostrictive energy
The change in length along the direction of magnetization of a domain solid refers to magnetostriction .notably we can see this in nickel and ferrites. So if a rod or tube of nickel is brought in to a magnetic field parallel to its length change slightly. The change in length is independent of the sign of field and may be either decrease or an increase depending upon the nature of the material.
Thus the magnetostriction in the domains. This energy will affect the growth of domains.
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