MS&E #4 Defects

27 flashcards · Physics · by Kristóf Nagy

1. weight percent (wt%)

   A way to express the composition of a material in terms of the ratio of the mass of a specific element to the total mass of the sample, typically multiplied by 100.

2. solute

   The minority constituent added to a solid solution, usually having a lesser proportion compared to the majority component (solvent).

3. scanning probe microscope (SPM)

   A class of microscopes utilizing a sharp probe to physically interact with a sample and acquire information regarding its morphology, electrical, or magnetic properties.

4. solvent

   The major constituent of a solid solution, providing a matrix for the solute atoms to incorporate into.

5. self-interstitial

   A point defect in which an atom from the crystal lattice occupies an interstitial position, leading to local strain.

6. mixed dislocation

   A composite dislocation comprising both edge and screw components, displaying a mix of their corresponding behaviors.

7. scanning electron microscope (SEM)

   A type of electron microscope that uses a focused beam of electrons to scan the surface of a sample and generate a high-resolution image based on secondary electron signals.

8. imperfection

   Any deviation from perfect periodicity in a crystal lattice, including point defects, dislocations, and grain boundaries.

9. grain size

   The average dimension of grains (crystallites) in a polycrystalline material, often reported in terms of the number of grains per unit area.

10. edge dislocation

    A type of dislocation characterized by an additional partial atomic plane inserted into the crystal lattice, creating a step-like disturbance.

11. dislocation line

    A line that defines the center of a dislocation and separates the distorted and undistorted regions of the crystal lattice.

12. composition

    The relative content of one or multiple constituents in a material, often expressed as weight percent or atom percent.

13. Burgers vector (b)

    A vector that describes the magnitude and direction of a dislocation's lattice distortion.

14. Boltzmann's constant (k)

    A fundamental physical constant that appears in statistical thermodynamics and quantum mechanics. Its value is approximately 1.38 * 10^(-23) J/K or 8.62 * 10^(-5) eV/K.

15. atom percent (at%)

    A way to express the composition of a material in terms of the ratio of the number of atoms of a specific element to the total number of atoms in the sample, typically multiplied by 100.

16. atomic vibration

    The rapid movement of atoms in a solid material around their lattice positions due to thermal energy.

17. screw dislocation

    A type of dislocation featuring a spiral-like distortion of the crystal lattice around the dislocation line, causing the lattice planes to rotate gradually.

18. photomicrograph

    A picture obtained using a microscope, often captured on film or digitally.

19. alloy

    A metallic substance composed of two or more elements.

20. microstructure

    The internal structure of a material at the microscale, revealing features like grains, precipitates, and dislocations.

21. solid solution

    A homogenous mixture of two or more elements or compounds in a solid phase, forming a single phase with altered properties compared to the individual components. There are two primary types: substitutional and interstitial solid solutions.

22. point defect

    A type of imperfection affecting only one or two atomic sites in a crystal lattice, including vacancies and self-interstitials.

23. substitutional solid solution

    A type of solid solution in which solute atoms replace solvent atoms in the crystal lattice, maintaining overall lattice integrity.

24. transmission electron microscope (TEM)

    A type of electron microscope that utilizes a beam of electrons transmitted through a thin sample to obtain detailed imagery and analyze its structure and composition.

25. interstitial solid solution

    A type of solid solution in which solute atoms occupy spaces (interstices) between solvent atoms, leading to local strain.

26. microscopy

    The scientific discipline concerned with obtaining and analyzing visual information about objects at a very small scale, often requiring specialized instruments.

27. vacancy

    A point defect in a crystal lattice created by the absence of an atom from its usual position, leaving a vacant site.