Weiss domains

Weiss domains are small areas in a crystal structure

Crystal structure

In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...

 of a ferromagnetic

Ferromagnetism

Ferromagnetism is the basic mechanism by which certain materials form permanent magnets and/or exhibit strong interactions with magnets; it is responsible for most phenomena of magnetism encountered in everyday life...

 material with uniformly oriented magnetic momenta. They were named after the French physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

 Pierre-Ernest Weiss (1865–1940).

Weiss discovered in 1907 that the magnetic moment

Magnetic moment

The magnetic moment of a system is a measure of the strength and the direction of its magnetism. More technically , the term magnetic moment of a system usually refers to its magnetic dipole moment, and quantifies the contribution...

 of atoms ("elementary magnets") of ferromagnetic materials become oriented, even without an external magnetic field

Magnetic field

Magnetic fields surround magnetic materials and electric currents and are detected by the force they exert on other magnetic materials and moving electric charges...

. The size of these oriented domains is in the range of 10^-3 to 10^-5 mm including a volume of about 10⁶ to 10⁹ atoms. The orientation is related to the crystal structure of the material.

By nature the Weiss domains are magnetized to the full saturation

Saturation (magnetic)

Seen in some magnetic materials, saturation is the state reached when an increase in applied external magnetizing field H cannot increase the magnetization of the material further, so the total magnetic field B levels off...

.

Weiss domains are small areas in a crystal structure

Crystal structure

In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a motif, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...

 of a ferromagnetic

Ferromagnetism

Ferromagnetism is the basic mechanism by which certain materials form permanent magnets and/or exhibit strong interactions with magnets; it is responsible for most phenomena of magnetism encountered in everyday life...

 material with uniformly oriented magnetic momenta. They were named after the French physicist

Physicist

A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

 Pierre-Ernest Weiss (1865–1940).

Weiss discovered in 1907 that the magnetic moment

Magnetic moment

The magnetic moment of a system is a measure of the strength and the direction of its magnetism. More technically , the term magnetic moment of a system usually refers to its magnetic dipole moment, and quantifies the contribution...

 of atoms ("elementary magnets") of ferromagnetic materials become oriented, even without an external magnetic field

Magnetic field

Magnetic fields surround magnetic materials and electric currents and are detected by the force they exert on other magnetic materials and moving electric charges...

. The size of these oriented domains is in the range of 10^-3 to 10^-5 mm including a volume of about 10⁶ to 10⁹ atoms. The orientation is related to the crystal structure of the material.

By nature the Weiss domains are magnetized to the full saturation

Saturation (magnetic)

Seen in some magnetic materials, saturation is the state reached when an increase in applied external magnetizing field H cannot increase the magnetization of the material further, so the total magnetic field B levels off...

. The boundaries between the domains are called Bloch wall

Bloch wall

A Bloch wall is a narrow transition region at the boundary between magnetic domains, over which the magnetization changes from its value in one domain to that in the next. The magnetization rotates through the plane of the wall unlike the Néel wall where the magnetization rotates in the plane of...

s.

Weiss domains are also found in ferroelectric materials (the electrical analogue of ferromagnetic materials), where the ferroelectric domains align to from regions of uniform dipole orientation.