維加德定律

是指同晶體結構的原子形成的固溶體的點陣常數是兩者點陣常數的一個中間值·用Ag和Cu的原子坐標可以寫成a=x1a1+x2a2

x1,x2,a1,a2分別指兩種單質的百分含量和點陣常數.

一般寫成:a=x1a1+(1-x1)a2

因為X1+X2=1,有時把X寫成C

In metallurgy, Vegard's law is an approximate empirical rule which holds that a linear relation exists, at constant temperature, between the crystal lattice parameter of an alloy and the concentrations of the constituent elements.

For example, consider the semiconductor compound InPxAs1-x. A relation exists between the constituent elements and their associated lattice parameters, a, such that:

aInPAs = xaInP + (1 − x)aInAs

One can also extend this relation to determine semiconductor band gap energies. Using InPxAs1-x as before one can find an expression that relates the band gap energies, Eg, to the ratio of the constituents and a bowing parameter b:

維加德定律