Static sensitization, effect behavior

To separate the effects of static and dynamic disorder, and to obtain an assessment of the height of the potential barrier that is involved in a particular mean-square displacement (here abbreviated (x )), it is necessary to find a parameter whose variation is sensitive to these quantities. Temperature is the obvious choice. A static disorder will be temperature independent, whereas a dynamic disorder will have a temperature dependence related to the shape of the potential well in which the atom moves, and to the height of any barriers it must cross (Frauenfelder et ai, 1979). Simple harmonic thermal vibration decreases linearly with temperature until the Debye temperature Td below To the mean-square displacement due to vibration is temperature independent and has a value characteristic of the zero-point vibrational (x ). The high-temperature portion of a curve of (x ) vs T will therefore extrapolate smoothly to 0 at T = 0 K if the sole or dominant contribution to the measured (x ) is simple harmonic vibration ((x )y). In such a plot the low-temperature limb is expected to have values of (x ) equal to about 0.01 A (Willis and Pryor, 1975). Departures from this behavior indicate more complex motion or static disorder. 

Static reactors are most useful for comparatively slow reactions, or for characterizing explosion behavior (Fig. 13.4). Typical reaction times are seconds to minutes. However, due to a high sensitivity to surface effects, static reactor experiments are generally not as useful for quantitative analysis as alternative techniques. 

Here N(x) is the potential energy barrier between reactant and product state of the hydrogen and E is the particle energy. For a static square barrier the theory predicts a huge non-realistic isotope effect and its non-sensitivity to temperature. The thermal fluctuations produce a thermal distribution of the transfer distance, /. For a rectangular barrier and low frequency vibration of substrate and medium and harmonic behavior of l ... 

Transducers based on diverse effects differ in efficiency, static output characteristics (linear, exponential, etc.), dynamic behavior (time constants, bandwidth, etc.), and cross sensitivity to the influence of interfering factors (e.g., tempera-... 

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