QUASICRYSTALS Meaning and
Definition
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Quasicrystals refer to a distinct form of solid material whose atomic structure exhibits certain unique properties that set them apart from ordinary crystals. In 1982, the Israeli scientist Dan Shechtman discovered quasicrystals, challenging the conventional belief that all crystals consist of repeating patterns of molecules. Unlike regular crystals, which possess symmetric and repetitive arrangements of atoms, quasicrystals exhibit a form of long-range order that is aperiodic, meaning it does not exhibit distinct repetitive patterns. Instead, quasicrystals possess a non-repeating yet highly ordered arrangement of atoms that demonstrate rotational symmetry, also known as five-fold rotational symmetry.
The atomic structure of quasicrystals reveals a remarkable organization that is intricately interwoven and exhibits a complex and beautiful geometrical pattern known as a Penrose tiling. This unique structure enables quasicrystals to possess certain atypical physical characteristics, such as high hardness, low friction, and unusual electrical and thermal properties.
While quasicrystals initially defied the principles of crystallography and were met with skepticism, their discovery and subsequent research have revolutionized our understanding of solid-state physics. Quasicrystals have broad applications in various fields, including material science, chemistry, and engineering. They find their usage in coatings, energy-efficient LED lights, catalysis, and even as components in advanced alloys. The study of quasicrystals continues to be an active area of research, unlocking further insight into fundamental principles regarding atomic structure, symmetry, and the physical properties of materials.
Etymology of QUASICRYSTALS
The word "quasicrystals" is derived from the term "quasiperiodic crystals", which was coined by the American mathematician and physicist Roger Penrose in the late 1970s. The term refers to a type of crystal that exhibits long-range order but is not characterized by a repeating unit cell like regular crystals. The prefix "quasi-" means "almost" or "pseudo", indicating that quasicrystals have characteristics resembling crystals, but not exactly. The term was later shortened to "quasicrystals" for brevity and ease of use.
