THE STUDY OF THE KINETICS AND THE MECHANISM OF DEHYDROXYLATION IN MUSCOVITE BY ESR ON FE3+

Dehydroxylation of muscovite in the form of small lamellae at 933 <T < 1173 K was studied by Electron Spin Resonance (ESR) on Fe3+. The kinet ics of the process has been established to be described by the model o f continuous nucleation on the large surface planes of the small plate s. Determined by experimental data the rate constant of the process k is shown to be that of dehyroxylation itself The artivation energy Obt ained by data at T<1100 K is 97.5 KJ.mol(-1). The nonlinear dependence of ln(k) on 1/T is explained by the theory of transitions induced by the fluctuative preparation of a potential barrier as a result of ther mal oscillations of ions in the lattice. At high temperatures the pote ntial curve of the hydroxyl's proton is transformed so that it can ove rcome the barrier from one potential well to the other (from one hydro xyl site to the adjacent one). Such transformations of the curve can b e caused by the oscillations of large structural clusters (similar to 1.10(-22) kg) with the frequency similar to 4.5.10(12) s(-1).