Pseudomorph

Definitions

  • Webster's Revised Unabridged Dictionary
    • Pseudomorph (Crystallog) A pseudomorphous crystal, such as a crystal consisting of quartz, but having the cubic form of fluor spar, the fluor crystal having been changed to quartz by a process of substitution.
    • Pseudomorph An irregular or deceptive form.
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Century Dictionary and Cyclopedia
    • n pseudomorph A deceptive, irregular, or false form; specifically, in mineralogy, a mineral having a definite form belonging, not to the substance of which it consists, but to some other substance which has wholly or partially disappeared. Sometimes quartz is found in the form of fluor-spar crystals, the fluor-spar having been changed by a process of substitution into quartz. Such crystals are pseudomorphs by substitution; another illustration is that of tinstone, cassiterite, after orthoclase feldspar. A more common and important class of pseudomorphs includes those formed by the chemical alteration of the original mineral: these are illustrated by pseudomorphs of native copper after the oxid cuprite, where there has been a simple loss of one ingredient, in this case oxygen; also, of gypsum after anhydrite, where the anhydrous calcium sulphate has been changed by assumption of water to the hydrous sulphate; or, still more important, where there has been a more or less complete exchange of constituents, as of the lead carbonate cerusite after the lead sulphid galena, or of serpentine after chrysolite, or of kaolin after feldspar, etc. Pseudomorphs are also formed by molecular change without change of chemical substance, as of calcite after aragonite, or rutile after brookite; these last are also called paramorphs. (See paramorphism.) Pseudomorphs very commonly have a noncrystalline waxy structure, but this is not necessarily the case.
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Etymology

Webster's Revised Unabridged Dictionary
See Pseudomorphous

Usage


In science:

As, in the case of pseudomorphic growth, the system has the translational invariance in the plane of the quantum well, the center of mass motion is still separable.
Exciton Spin Dynamics in Semiconductor Quantum Wells
It is worth noting that the diffusion barrier for Ag on top of a pseudomorphic layer of Ag on Pt (111) is substantially lower than that for Ag on Ag (111). A question that arises is whether this reduced diffusion barrier is a result of the compressive strain or electronic effects due to the Pt substrate.
Density-Functional Theory of Surface Diffusion and Epitaxial Growth of Metals
During deposition of the first layer the fcc site is energetically preferred compared to the hcp site, and the film growth pseudomorphically with the atoms in the fcc sites.
Density Functional Theory of Epitaxial Growth of Metals
Thus, it is predicted that for pseudomorphic Ag films (with increased parallel lattice constant) self-diffusion should get noticeably affected by the exchange mechanism.
Density Functional Theory of Epitaxial Growth of Metals
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