Solid State Diffusion
Solid State Diffusion - Related Videos
05:20
Characterization of Thermal Transport in One-dimensional Solid Materials
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Cited by 20 •
2014
The TET (transient electro-thermal) technique is an effective approach developed to measure the thermal diffusivity of solid materials.
03:31
Diffusion and Osmosis - Concepts
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2019
Cell Membranes and Diffusion In order to function, cells are required to move materials in and out of their cytoplasm via their cell membranes. These membranes are semipermeable, meaning that certain molecules are allowed to pass through, but not others. This movement of molecules is mediated by the phospholipid bilayer and its embedded proteins, some of which act as transport channels for molecules that otherwise would not be able to pass through the membrane, such as ions and carbohydrates.
08:18
Diffusion and Osmosis - Student Protocol
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2019
Diffusion in Agar ExpandNOTE: In this exercise, you will be given agar containing an indicator chemical called phenolphthalein. When phenolphthalein is exposed to the normal alkaline conditions in the agar, it will look pink. But when it is exposed to neutral or acidic conditions, it changes from pink to clear. You will make different size and shaped agar cubes as a model for cells to study the impact of cell size and shape on diffusion rate. To make the first set of cells, measure out and cut...
02:37
Metallic Solids
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2020
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties. All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
02:22
Structures of Solids
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2020
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
FAQs
Vacancy exchange occurs when an atom moves into an unoccupied lattice site, while interstitial hopping occurs when a smaller particle moves between available spaces within the lattice. These mechanisms provide distinct pathways for migration through a solid. Their availability helps determine whether atoms, ions, or molecules can move readily under particular structural and compositional conditions.
Temperature, concentration gradients, and the availability of diffusion pathways are the principal controls identified for this process. Higher temperature can promote atomic mobility, while concentration differences provide a driving influence for redistribution. The structure of the solid also matters because accessible pathways determine how readily particles can migrate through the crystal lattice.
Diffusion pathways connect regions of a solid where composition or structure differs, allowing particles to redistribute rather than remain fixed in place. This mobility can change local composition, influence crystal structure, and affect reactivity. Consequently, pathway availability helps determine whether processes such as phase transformations, alloy formation, or sintering can proceed effectively.
Adjusting temperature changes the mobility of particles, whereas establishing or modifying a concentration gradient affects the direction and extent of redistribution. Considering both variables helps researchers control how composition develops within a solid. This is relevant when seeking particular material properties, because diffusion can alter structure, reactivity, and the placement of chemically important species.
Solid state diffusion contributes to phase transformations, sintering, alloy formation, ionic transport, and the movement of dopants in semiconductors. In each case, particle migration changes composition or structure within a solid. Recognizing this dependence helps connect atomic-scale mobility with macroscopic material behavior, including the development of ceramics, catalysts, batteries, and semiconductor materials.
Chemists and materials researchers consider diffusion when designing systems whose performance depends on controlled chemical composition and atomic mobility. The process helps explain how ions move in batteries, how dopants distribute in semiconductors, and how composition changes during alloy formation or sintering. These connections make diffusion a framework for relating material structure to reactivity and function.