Introduction to Magnetic Materials

<p>The relationship between magnetic flux density and magnetic field strength. (A)</p> Signup and view all the answers

<p>The magnetization that remains after an external magnetic field is removed. (D)</p> Signup and view all the answers

<p>They become weakly magnetized in the presence of a magnetic field. (D)</p> Signup and view all the answers

<p>Magnetic moments are aligned in the same direction. (B)</p> Signup and view all the answers

<p>Induced currents in conductors exposed to changing magnetic fields. (C)</p> Signup and view all the answers

<p>It indicates ferromagnetic interaction. (B)</p> Signup and view all the answers

<p>The resistance to demagnetization when the magnetic field is removed. (A)</p> Signup and view all the answers

<p>The material repels magnetic fields. (B)</p> Signup and view all the answers

<p>They are directly proportional. (C)</p> Signup and view all the answers

<p>They retain magnetization after the removal of the magnetic field. (A)</p> Signup and view all the answers

<p>They can be permanently magnetized and have a high susceptibility. (C)</p> Signup and view all the answers

<p>Ferrimagnetic (A)</p> Signup and view all the answers

<p>They have a net magnetization that is zero at absolute zero. (A)</p> Signup and view all the answers

<p>They do not retain magnetization once the magnetic field is removed. (D)</p> Signup and view all the answers

<p>The effective magnetic moment of the material. (C)</p> Signup and view all the answers

<p>Magnetite (A)</p> Signup and view all the answers

<p>Exchange interaction leading to paramagnetism (D)</p> Signup and view all the answers

<p>They exhibit permanent magnetization. (B)</p> Signup and view all the answers

<p>Electron spin (C)</p> Signup and view all the answers

<p>The ratio of magnetization to magnetic field strength (C)</p> Signup and view all the answers

<p>Amperes per meter (B)</p> Signup and view all the answers

<p>B = μ * H (B)</p> Signup and view all the answers

<p>The permeability of a material compared to vacuum (B)</p> Signup and view all the answers

<p>Both intrinsic spin and orbital motion (B)</p> Signup and view all the answers

<p>They are randomly oriented, canceling out the net magnetic moment (B)</p> Signup and view all the answers

<p>How easily it can be magnetized (D)</p> Signup and view all the answers

An intrinsic property of electrons that creates a magnetic moment, making each electron act like a tiny magnet.

Measures the intensity of a magnetic field generated by currents or magnetic materials, measured in amperes per meter (A/m).

Represents the amount of magnetic field passing through a unit area, measured in teslas (T).

Indicates how easily a material can be magnetized or support a magnetic field, expressed in H/m.

A measure of how easily a material becomes magnetized in an applied magnetic field, the ratio of magnetization (M) to field strength (H).

The permeability of a material in vacuum.

Ratio of a material's permeability to that of vacuum.

The movement of electrons around the nucleus creates a current loop and contributes to the atom's magnetic moment.

The extent to which a material becomes magnetized in an external magnetic field, measured in amperes per meter (A/m).

The magnetic field strength needed to demagnetize a material after it's been fully magnetized.

The magnetization left in a material after the external magnetic field is removed.

The maximum magnetization a material can achieve in a magnetic field.

The temperature at which a ferromagnetic material loses its permanent magnetism and becomes paramagnetic.

Materials weakly repelled by magnetic fields.

Materials weakly attracted to magnetic fields, but magnetism disappears without external field.

Regions within a material where magnetic moments of atoms are aligned in the same direction.

Materials that can be permanently magnetized, exhibit strong magnetization due to aligned magnetic domains, and have high susceptibility. Examples: Iron, nickel, and cobalt.

Similar to ferromagnetic materials, but with two or more types of ions with opposing magnetic moments, creating a net magnetization. Example: Magnetite (Fe₃O₄).

Materials with neighboring magnetic moments aligned in opposite directions, canceling each other out. No net magnetization at absolute zero. Example: Manganese oxide (MnO).

Small ferromagnetic or ferrimagnetic nanoparticles with a single magnetic domain. Magnetized by external fields but lose magnetization when the field is removed. Example: Iron oxide nanoparticles.

Describes the relationship between magnetization and temperature in a paramagnetic material, taking into account the exchange interaction.

A proportionality constant in Curie Law, calculated using the effective magnetic moment, number density of magnetic moments, and Boltzmann constant.

A quantum mechanical force that causes interaction between magnetic moments, influencing their alignment in ferromagnetic and antiferromagnetic materials.

The state of a material above its Curie temperature, where individual magnetic moments are not aligned but can be weakly magnetized by an external field.

A constant in the Curie-Weiss law representing the temperature at which a material's magnetic susceptibility would theoretically become infinite. It indicates the strength of magnetic interactions within the material.

Ferromagnetic materials have a Curie-Weiss temperature greater than zero (θ > 0), indicating parallel alignment of magnetic moments. Antiferromagnetic materials have a negative Curie-Weiss temperature (θ < 0), indicating antiparallel alignment of magnetic moments.

A measure of the intrinsic magnetic moment of an atom or ion, calculated from the slope of the magnetic susceptibility vs. temperature curve. Represents the strength of the magnetic dipole moment contributing to magnetism.