Untitled Quiz

The displacement distance of atoms around a dislocation line. It's perpendicular to the edge dislocation line.

A type of line defect formed by applying shear stress to a perfect crystal, causing a helical path in the crystal lattice.

Imperfections in the crystal structure that occur at a single atomic site.

One-dimensional imperfections that disrupt the crystal lattice, like dislocations. They influence material properties.

The deliberate introduction of impurities into a semiconductor to alter its electrical, optical, and structural properties.

Impurity atoms added to a semiconductor during doping, which contribute extra electrons (n-type) or holes (p-type) to the material.

A semiconductor material doped with impurities that have a higher valence than the base element, resulting in an excess of free electrons, making it more conductive.

A semiconductor material doped with impurities that have a lower valence than the base element, resulting in an excess of 'holes' (electron vacancies), allowing for better conductivity.

The energy level at which there is a 50% probability of finding an electron in a material at absolute zero temperature. It shifts upon doping.

Resistivity (ρ) is a material property that describes how strongly a material opposes the flow of electric current. Resistance (R) is a measure of how much a specific object made of that material opposes the current. Resistance is calculated as R = ρL/A, where L is the length and A is the cross-sectional area.

A material that allows electric current to flow easily through it, with low resistance.

A material that strongly resists the flow of electric current, having very high resistance.

Electrons located in the outermost shell of an atom. They're responsible for bonding with other atoms and determining the electrical properties of a material.

A rule stating that atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight electrons in their outermost shell.

Materials that can act as both conductors and insulators, depending on conditions like temperature or impurities. Their conductivity falls between conductors and insulators.

The arrangement of atoms and the freedom of electrons within those materials determine their electrical properties. In conductors, electrons move freely, in semiconductors, their movement is more restricted, and in insulators, electrons are tightly bound.

The pressure exerted by the vapor of a substance in equilibrium with its liquid or solid phase at a given temperature.

The process where a substance changes directly from the solid state to the gaseous state without passing through the liquid state.

A material's property describing how its resistance changes with temperature. It's represented by 'a' and measured in per degree Celsius (°C).

The resistance of a material changes with temperature. The formula for calculating resistance at a different temperature is R = Ro(1 + aΔT), where Ro is the initial resistance, a is the temperature coefficient of resistance, and ΔT is the temperature change.

The tendency of matter to increase in length when heated. The amount of expansion depends on the material's coefficient of linear expansion and the temperature change.

The tendency of matter to increase in volume when heated. The amount of expansion depends on the material's coefficient of volumetric expansion and the temperature change.

A material property that indicates how much it expands per degree Celsius change in temperature. Each material has its unique a value.

A material property that indicates how much its volume expands per degree Celsius change in temperature. Each material has its unique 'b' value.

The formula R = Ro(1 + aΔT) is used to calculate the resistance of a material at a different temperature, where Ro is the initial resistance, a is the temperature coefficient of resistance, and ΔT is the temperature change.

Temperature affects the physical properties of materials, including resistance and expansion. These changes are predictable and can be calculated using specific formulas and material properties.

The bending of light as it passes from one medium to another, caused by a change in its speed.

A dimensionless number that describes how much a material slows down light compared to a vacuum.

N = C/V, where N is the refractive index, C is the speed of light in a vacuum, and V is the speed of light in the material.

Refraction, because light bends as it passes from air (faster) into water (slower).

The characteristics of materials describing how they interact with light.

The gradual deterioration of a material due to a chemical reaction with its environment.

A numerical value representing a material's resistance to corrosion.

The speed of light decreases in a medium with a higher refractive index.

A point defect in a crystal lattice where an atom is missing from its usual position, creating a vacant site. This lowers the density of the material.

A point defect where an extra atom or molecule occupies a space between the regular lattice sites, increasing the material's density.

A point defect in ionic solids where a smaller ion (usually a cation) leaves its lattice site and occupies an interstitial space. This creates both a vacancy and an interstitial defect.

A point defect in ionic solids where an equal number of cations and anions are missing from their lattice sites, maintaining electrical neutrality. It's like a balanced pair of missing tiles.

A type of line defect where the lattice structure near the defect line is distorted towards or away from the line. It's like the tiles around a crack are pushed or pulled.

Point defects are localized imperfections in a crystal lattice. Common types include vacancy defects (missing atoms), interstitial defects (extra atoms), Frenkel defects (an ion moving to an interstitial space), and Schottky defects (balanced missing ions).

Line defects, like edge defects, disrupt the crystal lattice along a line. These defects can influence the material's strength, ductility, and other mechanical properties.