Lindemann criterion

The Lindemann criterion (after Frederick Lindemann ) is a criterion for the melting of solids : the fixed order of the crystal collapses when

${\displaystyle x_{max}>(0,2\dots 0,3)\cdot a}$

With

• the maximum displacement of the lattice atoms ${\displaystyle x_{max}}$
• the lattice constants . ${\displaystyle a}$

For example, the oscillation amplitude of helium atoms at normal pressure is also approximately at absolute zero ( zero point oscillation ). No solid phase can therefore form, this only occurs at pressures above 25  bar . ${\displaystyle x_{max}\approx (0,3\dots 0,4)\cdot a}$

literature

• Rudolf Gross, Achim Marx: Solid State Physics. Oldenbourg, 2012, p. 115