STRUCTURAL AND DENSITY CHANGES OF AMORPHOUS FILMS OF ALUMINA AT ELECTRON-BEAM ANNEALING

Amorphous films of alumina (Al2O3) were investigated at electron-beam annealing. TEM studies with “in situ” video recording of structural changes demonstrated, that phase transformation of alumina is the island polymorphous crystallization mode with the relative length δ0 ≈ 70. The dependence on time of the fraction of the crystalline phase has an exponential character, described by the JMAK formula with a rate constant k = 0.058 s-2 and Avrami exponent n = 2.01. The density of the crystalline film exceeds the density of the amorphous film. The relative change of the density of the film substance after crystallization is (10.4 ±1.7)%.