Ideal crystal:
1) A crystal with a perfect three-dimensionally periodic lattice throughout its volume, free of any structural defects — vacancies, impurity atoms, dislocations and others. The concept of an “ideal crystal” is widely used in crystallography and in the theory of the solid state, but it is an idealisation, since real crystals always contain a certain number of defects that are in thermodynamic equilibrium with the lattice. Closest in structure to an ideal crystal are the so-called dislocation-free crystals (Si, Ge) and whisker crystals.
2) A crystal of perfect form, in which physically equivalent faces are equally developed (see Crystallisation).
1) A crystal with a perfect three-dimensionally periodic lattice throughout its volume, free of any structural defects — vacancies, impurity atoms, dislocations and others. The concept of an “ideal crystal” is widely used in crystallography and in the theory of the solid state, but it is an idealisation, since real crystals always contain a certain number of defects that are in thermodynamic equilibrium with the lattice. Closest in structure to an ideal crystal are the so-called dislocation-free crystals (Si, Ge) and whisker crystals.
2) A crystal of perfect form, in which physically equivalent faces are equally developed (see Crystallisation).