Magnetic Susceptibility

Magnetic susceptibility is a measure of the degree to which a material can be magnetized. It is a dimensionless quantity that is defined as the ratio of the magnetization of a material to the magnetic field strength applied to it.

Diamagnetism

Diamagnetism is a type of magnetism that is exhibited by all materials. It is caused by the tendency of the electrons in a material to oppose the applied magnetic field. Diamagnetism is a weak form of magnetism, and it is typically only observed in materials that are not ferromagnetic or paramagnetic.

Paramagnetism

Paramagnetism is a type of magnetism that is exhibited by materials that have unpaired electrons. These unpaired electrons create small magnetic moments that align with the applied magnetic field. Paramagnetism is a stronger form of magnetism than diamagnetism, but it is still relatively weak.

Ferromagnetism

Ferromagnetism is a type of magnetism that is exhibited by materials that have a strong magnetic moment. This strong magnetic moment is caused by the alignment of the magnetic moments of the unpaired electrons in the material. Ferromagnetism is the strongest form of magnetism, and it is responsible for the permanent magnets that we use in everyday life.

Magnetic susceptibility is a fundamental property of materials that can be used to understand their magnetic behavior. It has a wide range of applications, from medical imaging to transportation.

Formula of Magnetic Susceptibility

Magnetic susceptibility is a measure of the degree to which a material can be magnetized. It is defined as the ratio of the magnetization of a material to the magnetic field strength applied to it. The SI unit of magnetic susceptibility is henry per meter (H/m).

Formula

The formula for magnetic susceptibility is:

$$\chi = \frac{M}{H}$$

where:

• $\chi$ is the magnetic susceptibility (H/m)
• $M$ is the magnetization of the material (A/m)
• $H$ is the magnetic field strength (A/m)

Units

The SI unit of magnetic susceptibility is henry per meter (H/m). However, magnetic susceptibility is often expressed in dimensionless units, such as emu/g (electromagnetic units per gram) or SI units, such as m$^3$/mol (cubic meters per mole).

Temperature Dependence

The magnetic susceptibility of a material is typically temperature dependent. In general, the magnetic susceptibility of a material decreases with increasing temperature. This is because the thermal energy of the atoms in the material tends to disorder the magnetic moments of the atoms, making it more difficult for the material to be magnetized.

Magnetic susceptibility is a fundamental property of materials that can be used to understand their magnetic behavior. The formula for magnetic susceptibility is $\chi = \frac{M}{H}$, where $\chi$ is the magnetic susceptibility, $M$ is the magnetization, and $H$ is the magnetic field strength. Magnetic susceptibility is typically temperature dependent, and it has a variety of applications, including MRI, magnetic separation, and maglev.

Unit of Magnetic Susceptibility

Magnetic susceptibility is a measure of the degree to which a material can be magnetized. It is a dimensionless quantity, and its SI unit is henries per meter (H/m).

SI unit of Magnetic Susceptibility

The SI unit of magnetic susceptibility is henries per meter (H/m). This unit can be derived from the following equation:

$$\chi_m = \frac{M}{H}$$

where:

• $\chi_m$ is the magnetic susceptibility
• $M$ is the magnetization of the material
• $H$ is the magnetic field strength

Other units of Magnetic Susceptibility

In addition to henries per meter, magnetic susceptibility can also be expressed in the following units:

• Cubic meters per kilogram (m$^3$/kg): This unit is often used in materials science and engineering.
• Cubic centimeters per gram (cm$^3$/g): This unit is sometimes used in chemistry and physics.
• Gauss per oersted (G/Oe): This unit is occasionally used in geomagnetism and paleomagnetism.

Conversion between units of Magnetic Susceptibility

The following table shows how to convert between different units of magnetic susceptibility:

From	To	Multiply by
H/m	m$^3$/kg	1000
H/m	cm$^3$/g	10$^6$
H/m	G/Oe	4$\pi$ x 10$^{-7}$
m$^{3}$/kg	H/m	0.001
m$^{3}$/kg	cm$^3$/g	1000
m$^3$/kg	G/Oe	4$\pi$ x 10$^{-10}$
cm$^3$/g	H/m	10$^{-6}$
cm$^3$/g	m$^3$/kg	0.001
cm$^3$/g	G/Oe	4$\pi$ x 10$^{-13}$
G/Oe	H/m	2.54 x 10$^6$
G/Oe	m$^3$/kg	2.54 x 10$^9$
G/Oe	cm$^3$/g	2.54 x 10$^{12}$

Facts on Magnetic Susceptibility

Magnetic susceptibility is a measure of how easily a material can be magnetized. It is a dimensionless quantity that is defined as the ratio of the magnetization of a material to the magnetic field strength applied to it.

Diamagnetism

• Diamagnetism is a type of magnetism that occurs in all materials. It is caused by the motion of electrons in atoms and molecules. When a magnetic field is applied to a diamagnetic material, the electrons move in such a way that they create a magnetic field that opposes the applied field. This results in a very weak magnetic susceptibility.

Paramagnetism

• Paramagnetism is a type of magnetism that occurs in materials that have unpaired electrons. When a magnetic field is applied to a paramagnetic material, the unpaired electrons align themselves with the field. This results in a positive magnetic susceptibility.

Ferromagnetism

• Ferromagnetism is a type of magnetism that occurs in materials that have a strong magnetic moment. This is due to the fact that the magnetic moments of the atoms in a ferromagnetic material are aligned in the same direction. Ferromagnetic materials have a very high magnetic susceptibility.

Antiferromagnetism

• Antiferromagnetism is a type of magnetism that occurs in materials that have a strong magnetic moment, but the magnetic moments of the atoms are aligned in opposite directions. This results in a zero magnetic susceptibility.

Ferrimagnetism

• Ferrimagnetism is a type of magnetism that occurs in materials that have a strong magnetic moment, but the magnetic moments of the atoms are not aligned in the same direction. This results in a non-zero magnetic susceptibility.

Applications of Magnetic Susceptibility

Magnetic susceptibility is used in a variety of applications, including:

• Magnetic resonance imaging (MRI): MRI is a medical imaging technique that uses magnetic fields and radio waves to create images of the inside of the body. Magnetic susceptibility is used to create contrast between different tissues in the body.
• Magnetic separation: Magnetic separation is a process that uses magnetic fields to separate materials that have different magnetic susceptibilities. This process is used in a variety of industries, including mining, recycling, and food processing.
• Magnetic levitation (maglev): Maglev is a transportation technology that uses magnetic fields to levitate trains above the tracks. This allows trains to travel at very high speeds with very little friction.

Magnetic Susceptibility FAQs

What is magnetic susceptibility?

Magnetic susceptibility is a measure of how easily a material can be magnetized. It is a dimensionless quantity that is defined as the ratio of the magnetization of a material to the magnetic field strength applied to it.

What are the different types of magnetic susceptibility?

There are three main types of magnetic susceptibility:

• Diamagnetism: Diamagnetism is a type of magnetic susceptibility that is exhibited by all materials. It is caused by the tendency of the electrons in a material to oppose the applied magnetic field. Diamagnetic materials have a negative magnetic susceptibility.
• Paramagnetism: Paramagnetism is a type of magnetic susceptibility that is exhibited by materials that have unpaired electrons. These electrons can be aligned with the applied magnetic field, which increases the magnetization of the material. Paramagnetic materials have a positive magnetic susceptibility.
• Ferromagnetism: Ferromagnetism is a type of magnetic susceptibility that is exhibited by materials that have a strong magnetic moment. These materials can be permanently magnetized, even in the absence of an applied magnetic field. Ferromagnetic materials have a very high positive magnetic susceptibility.

What are some of the applications of magnetic susceptibility?

Magnetic susceptibility is used in a variety of applications, including:

• Magnetic resonance imaging (MRI): MRI is a medical imaging technique that uses magnetic fields and radio waves to create images of the inside of the body. Magnetic susceptibility is used to create contrast between different tissues in the body.
• Magnetic separation: Magnetic separation is a process that uses magnetic fields to separate materials with different magnetic susceptibilities. This process is used in a variety of industries, including mining, recycling, and food processing.
• Magnetic levitation (maglev): Maglev is a transportation technology that uses magnetic fields to levitate trains above the tracks. This technology allows trains to travel at very high speeds with very little friction.

What are some of the factors that affect magnetic susceptibility?

The magnetic susceptibility of a material is affected by a number of factors, including:

• The temperature of the material: The magnetic susceptibility of a material decreases with increasing temperature. This is because the thermal energy of the atoms in the material causes them to become more disordered, which makes it more difficult for them to align with the applied magnetic field.
• The presence of impurities: The presence of impurities in a material can decrease its magnetic susceptibility. This is because the impurities can disrupt the alignment of the atoms in the material, which makes it more difficult for them to align with the applied magnetic field.
• The crystal structure of the material: The crystal structure of a material can affect its magnetic susceptibility. This is because the crystal structure determines the arrangement of the atoms in the material, which can affect their ability to align with the applied magnetic field.

Conclusion

Magnetic susceptibility is a fundamental property of materials that is used in a variety of applications. It is a measure of how easily a material can be magnetized, and it is affected by a number of factors, including the temperature of the material, the presence of impurities, and the crystal structure of the material.