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Chapter VII Reactivity at Dislocation….
single crystal [67-70], anthracene single crystals [71,72], calcite crystal cleavages
[73-78], Mn +2 and Cu +2 doped calcium L- tartrate crystals [79].
The Arrhenius equation is usually used today to interpret kinetic data, the
problem of temperature dependence of reaction was of great deal of controversy
and discussion during 1850 to 1910. Several empirical relations are well reported
and discussed in details by Laidler [80, 81]. The following reactions can be
considered for etch pits. Berthelot [82] proposed the equation,
W = Ae DT
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(7.13)
Where, W is the average width of etch pit, T is the absolute temperature, A
and D are constants. This equation was supported by results of Hood [83] and
the parameters could be determined by a plot of log W versus log T.
Harcourt and Esson [84] made their contributions to chemical kinetics by
formulating and applying the method of integration and suggested an equation
for temperature dependence in the following form:
W =AT m
(7.14)
Where, W is the average width of etch pit, T is the absolute temperature, A
and m are constants.
The parameters can be evaluated from the plots of log W versus log T. In
1898, Van’t Hoff [85] pointed out that most of the equations that had been
proposed for temperature dependence were special case of the following type
three parameter equations.
m 2
W AT exp B D T / T
(7.15)