An inert foreign substance added to a polymer to improve or modify
its properties.
Firing
A high temperature heat treatment that increases the density and
strength of a ceramic piece.
Flat-band potential
see under Electrolyte/Insulator/Silicon (EIS).
Flip-flop
binary device whose outputs change value only in response to an
input pulse.
Fluorescence
Luminescence (see also under"luminescence") which persists less
than a second after the exciting cause has been removed. If the
luminescence persists significantly longer it is called
phosphorescence.
FM
Frequency Modulation - information coding scheme in which the
frequency of a steady wave is changed.
Forward bias
The conducting bias for a p-n junction rectifier that assures
electron flow to the n side of the junction.
Free energy (G)
A thermodynamic quantity that is a function of the enthalpy (H),
the Kelvin temperature (T) and the entropy (S) of a system;
G=H-TS. At equilibrium, the free energy is at a minimum. Under
certain conditions the change in free energy for a process is
equal to the maximum useful work.
Frequency
Number of times per second that a quantity representing a signal,
such as a voltage, changes state. Also, the number of waves
(cycles) per second that pass a given point in space.
Frequency response
Two relations between sets of inputs and outputs. One relates
frequencies to the output-input amplitude ratio; the other relates
frequencies to the phase difference between the output and input.
