polycrystalline

Thân thiện

A polycrystalline metal sample shows many tiny grains under a microscope.

Definition

1. Adjective:
   • Composed of many small crystals: Describes a solid material whose structure consists of numerous crystalline grains or crystallites, as opposed to a single, continuous crystal (which is monocrystalline).

Usage

• The term is used primarily in materials science, metallurgy, and solid-state physics to describe the microstructure of a substance.
• It is typically used attributively (before a noun) to modify the name of a material.

Examples

• Adjective:
  • Solar panels often use polycrystalline silicon because it is more cost-effective to produce than monocrystalline silicon.
  • The polycrystalline structure of the metal was visible under the microscope.
  • Most common metals, like the steel in this bridge, are polycrystalline.

Advanced Usage

• "Polycrystalline aggregate": A common technical term for a solid composed of many crystalline grains.
  • The rock sample was identified as a polycrystalline aggregate of quartz and feldspar.
• The property of being polycrystalline is referred to as "polycrystallinity".

Variants and Related Words

• Monocrystalline (adj): Composed of a single, continuous crystal. (Antonym)
  • Monocrystalline silicon wafers have higher purity.
• Crystallite (n): A small, individual crystal grain within a polycrystalline material.
  • The size of the crystallites affects the material's strength.
• Grain (n): In this context, synonymous with crystallite; a single crystal region in a polycrystalline material.
  • The grain boundaries are where two crystals meet.

Synonyms

• Multicrystalline (adj): Often used interchangeably, especially regarding silicon for solar cells.
• Granular (adj): Can describe a similar visual or textural quality, though it is less specific to crystalline structure.

Notes

• Polycrystalline materials have grain boundaries, which are the interfaces where crystals of different orientations meet. These boundaries significantly influence the material's mechanical and electrical properties.
• The term is a technical adjective. Its use is almost entirely confined to scientific and engineering contexts describing the microstructure of solids like metals, ceramics, and semiconductors.

Học thuật

Adjective

1. composed of aggregates of crystals
   • polycrystalline metals