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Materials Science and Engineering/Doctoral review questions/Crystallography

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Tensor 1

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Propagation of Waves Along One-Dimensional Crystal with Two Kinds of Atoms

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  • Force-balance equations
  • Trial solution
  • With a given value of k, there are two different waves of angular frequency that may be propagated

Interpretation of the Solutions

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Solutions of Small k
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Solutions with positive sign at k = 0
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Solutions with negative sign at k = 0
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Acoustic and optic branch

Solutions with k = kmax
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Displacements at kmx
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Correspondence to the Identical-Atom Problem

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The optical mode is not present in the case with one kind of atom.

Tensor 2

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Wave Propagation in a Continuous One-Dimensional Medium

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The wave velocity is independent of

 

Wave Motion on a Row of Identical Atoms

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Total Number of Vibrational Modes that May be Supported by the Crystal

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The number of vibration modes that can be supported is equal to the number of atoms in the crystal

Tensor 3

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Propagation of Elastic Waves in Crystals

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Relation of stress and strain in a cubic crystal

Tensor 4

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Tensor 5

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Conventions of Relabeling Stress, Strain, Stiffness, and Compliance in Matrix Notation

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Condensation of Tensor to Matrix Notation

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Strain in Terms of Stress

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Stress in Terms of Strain

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Tensor 6

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Property Tensors

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Triclinic

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Monoclinic

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Orthorhombic

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Tetragonal

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Tetragonal

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Cubic

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Isotropic

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Cauchy Relation

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  1. Central Forces
  2. Each atom at center of symmetry
  3. No initial stress

Tensor 7

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Some Basic Relations in Electromagnetism

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