Paramagnetic

Definition

Paramagnetic materials are substances that are weakly attracted to an external magnetic field and can become magnetized in the presence of that field. This property arises from the atomic-level magnetic moments of the material's constituent atoms or molecules.

5 Must Know Facts For Your Next Test

1. Paramagnetic materials, such as aluminum, oxygen, and platinum, have unpaired electrons that create small magnetic moments that can align with an external magnetic field.
2. The strength of paramagnetism is directly proportional to the number of unpaired electrons in the material and the applied magnetic field strength.
3. Paramagnetic materials exhibit a positive magnetic susceptibility, meaning they are attracted to magnetic fields, but the effect is much weaker than in ferromagnetic materials.
4. Paramagnetic materials lose their induced magnetization when the external magnetic field is removed, unlike ferromagnetic materials which can retain their magnetization.
5. The paramagnetic effect is exploited in various applications, such as in the design of magnetic resonance imaging (MRI) machines and in the study of molecular structures using electron spin resonance spectroscopy.

Review Questions

• Explain how the atomic-level magnetic moments of a paramagnetic material contribute to its overall magnetic properties.
  • Paramagnetic materials contain atoms or molecules with unpaired electrons, which create small magnetic moments at the atomic level. When an external magnetic field is applied, these magnetic moments tend to align with the field, causing the material to become weakly magnetized. The strength of the paramagnetic effect is directly proportional to the number of unpaired electrons and the strength of the applied magnetic field. This atomic-level alignment of magnetic moments is what gives paramagnetic materials their characteristic weak attraction to external magnetic fields.
• Describe how the magnetic susceptibility of a paramagnetic material differs from that of a diamagnetic or ferromagnetic material.
  • Paramagnetic materials have a positive magnetic susceptibility, meaning they are weakly attracted to an external magnetic field. This susceptibility is much lower than that of ferromagnetic materials, which can become strongly magnetized. Diamagnetic materials, on the other hand, have a negative magnetic susceptibility, meaning they are weakly repelled by magnetic fields. The degree of magnetization in a paramagnetic material is directly proportional to the applied magnetic field strength, unlike ferromagnetic materials, which can retain their magnetization even when the external field is removed.
• Discuss the practical applications of the paramagnetic properties of materials, particularly in the context of 12.3 Magnetic Force between Two Parallel Currents and 12.7 Magnetism in Matter.
  • The paramagnetic properties of materials are exploited in various applications, including the design of magnetic resonance imaging (MRI) machines, which rely on the paramagnetic behavior of certain elements to generate the necessary magnetic fields. In the context of 12.3 Magnetic Force between Two Parallel Currents, the paramagnetic nature of some materials can influence the magnetic forces experienced by current-carrying conductors placed in close proximity. Additionally, in the study of 12.7 Magnetism in Matter, the paramagnetic behavior of materials is an important consideration, as it helps explain the magnetic properties of various substances and their interactions with external magnetic fields.

Related terms

Diamagnetism:

Diamagnetic materials are substances that are weakly repelled by an external magnetic field and cannot be magnetized.

Ferromagnetism: Ferromagnetic materials are strongly attracted to magnetic fields and can become permanently magnetized.

Magnetic Susceptibility:

The degree to which a material can be magnetized in response to an applied magnetic field, expressed as the ratio of the induced magnetization to the applied field.