Magnetic susceptibility

Definition

Magnetic susceptibility is a measure of how much a material will become magnetized in response to an applied magnetic field. It quantifies the degree to which a material can be magnetized and indicates whether the material is diamagnetic, paramagnetic, or ferromagnetic. Understanding magnetic susceptibility helps in categorizing materials based on their magnetic behavior under external influences.

5 Must Know Facts For Your Next Test

1. Magnetic susceptibility is denoted by the symbol \(\chi\) and can be either positive or negative depending on whether the material is paramagnetic or diamagnetic, respectively.
2. The value of magnetic susceptibility can vary significantly among different materials; for example, metals typically exhibit positive susceptibility, while most materials exhibit negative susceptibility.
3. In paramagnetic materials, the magnetic susceptibility is small and positive, reflecting their weak attraction to external magnetic fields, which enhances alignment with the field.
4. Diamagnetic materials have a magnetic susceptibility of less than zero, indicating a slight repulsion from external magnetic fields due to induced dipoles within the material.
5. Magnetic susceptibility plays a crucial role in applications like magnetic resonance imaging (MRI) and data storage technologies, where different materials' responses to magnetic fields are exploited.

Review Questions

• Compare and contrast the magnetic susceptibility of diamagnetic and paramagnetic materials in terms of their behavior in an external magnetic field.
  • Diamagnetic materials have negative magnetic susceptibility, meaning they are slightly repelled by an external magnetic field and do not retain any magnetization once the field is removed. In contrast, paramagnetic materials have positive magnetic susceptibility and are weakly attracted to an external magnetic field, aligning their unpaired electrons with the field. This fundamental difference in behavior defines how each type of material interacts with external magnetism.
• Evaluate how the concept of magnetic susceptibility applies to real-world applications such as MRI technology.
  • In MRI technology, different tissues and materials exhibit varying levels of magnetic susceptibility. For instance, fat has a different susceptibility compared to water or muscle tissue. This difference is utilized to create contrast in MRI images, allowing for better visualization of internal structures. By manipulating magnetic fields and radio waves based on the susceptibility differences, medical professionals can obtain detailed images for diagnosis.
• Synthesize your understanding of magnetic susceptibility by analyzing how it could affect material selection in designing electronic devices.
  • When designing electronic devices, understanding magnetic susceptibility is crucial for selecting materials that will not interfere with performance due to unwanted magnetic properties. For example, using diamagnetic materials may be favorable in sensitive electronic components to avoid unintended magnetization that could disrupt functionality. On the other hand, paramagnetic materials might be chosen for specific applications where their weak attraction can be harnessed effectively. Thus, engineers must consider magnetic susceptibility in their designs to optimize device performance and reliability.

Related terms

Diamagnetism: A form of magnetism that occurs in materials that are not attracted to a magnetic field and instead develop a weak repulsion when exposed to it.

Paramagnetism: A form of magnetism that occurs in materials that are weakly attracted to an external magnetic field due to the presence of unpaired electrons.

Ferromagnetism: A strong form of magnetism exhibited by materials like iron, cobalt, and nickel, where magnetic moments align parallel to each other even without an external field.