312
respectively the disproportionation reaction of Fe
2+
and the comproportionation (or anti-disproportionation) reaction of Fe
2+
.
Doping – An operation consisting of introducing in an intentional and controlled
manner a quantity of a foreign constituent (dopant) into a host (matrix). This
operation can considerably modify certain physical properties of the host. The
doping level is very low in materials for microelectronics (< 10
–6
). It reaches
the at% level in solid-state electrochemistry.
Effective charge – A charge attributed to a structure element (normal or defect) in
an ionic crystal. It depends on the real charge of the species that occupies a
given site and on the charge of the species that normally occupies the site in
a pure ionic crystal. The effective charge of a structure element can be positive, denoted “
•
,” negative, denoted “ ′ ,” or zero, denoted “
#
.” The electric
neutrality of an ionic crystal involves the effective charges of the species
present in the crystal.
Electrical conductivity – The electrical conductivity of a material is due to the displacement of electric charges (electrons, ions) when the material is subjected
to a gradient in the chemical potential or in the electrical potential. Its units
are siemens/meter [S m
–1
]. We generally use siemens/centimeter [S cm
–1
].
Electrical mobility – The speed of displacement of a charged species per unit
electric force.
Electrical resistivity – An intrinsic property of a material that represents its capacity to oppose the passage of an electric current. Its value is determined by
measuring the resistance R of a portion of the material with well-defined
geometry and is expressed in ohm meters (Ω m).
Electrochemical chain – A system consisting of two electrodes separated by one or
more electrolytes. An example is Ag / AgI / C, I 2 .
Electrochemical coloration – A change in color observed upon injecting electronic
charge carriers into a highly polarized electrolyte. The color change is attributed to the formation of color centers, which absorb in the visible light.
Electrochemical integrator – Device to measure a time delay after an electrochemical
response.
Electrochemical mobility – The speed of displacement of a charged species per unit
electric field.
Electrochemical pump – A device to extract or enrich a gas in a gaseous mixture in a
container of freely circulating. Schematically, it consists of a solid electrolyte
that isolates the gas to be enriched or purified. The solid electrolyte is used
as an ionic conductor with the charge carriers being the ions of the chemical
species to be introduced into or extracted from the gas. For example, stabilized
Solid-State Electrochemistry
respectively the disproportionation reaction of Fe
2+
and the comproportionation (or anti-disproportionation) reaction of Fe
2+
.
Doping – An operation consisting of introducing in an intentional and controlled
manner a quantity of a foreign constituent (dopant) into a host (matrix). This
operation can considerably modify certain physical properties of the host. The
doping level is very low in materials for microelectronics (< 10
–6
). It reaches
the at% level in solid-state electrochemistry.
Effective charge – A charge attributed to a structure element (normal or defect) in
an ionic crystal. It depends on the real charge of the species that occupies a
given site and on the charge of the species that normally occupies the site in
a pure ionic crystal. The effective charge of a structure element can be positive, denoted “
•
,” negative, denoted “ ′ ,” or zero, denoted “
#
.” The electric
neutrality of an ionic crystal involves the effective charges of the species
present in the crystal.
Electrical conductivity – The electrical conductivity of a material is due to the displacement of electric charges (electrons, ions) when the material is subjected
to a gradient in the chemical potential or in the electrical potential. Its units
are siemens/meter [S m
–1
]. We generally use siemens/centimeter [S cm
–1
].
Electrical mobility – The speed of displacement of a charged species per unit
electric force.
Electrical resistivity – An intrinsic property of a material that represents its capacity to oppose the passage of an electric current. Its value is determined by
measuring the resistance R of a portion of the material with well-defined
geometry and is expressed in ohm meters (Ω m).
Electrochemical chain – A system consisting of two electrodes separated by one or
more electrolytes. An example is Ag / AgI / C, I 2 .
Electrochemical coloration – A change in color observed upon injecting electronic
charge carriers into a highly polarized electrolyte. The color change is attributed to the formation of color centers, which absorb in the visible light.
Electrochemical integrator – Device to measure a time delay after an electrochemical
response.
Electrochemical mobility – The speed of displacement of a charged species per unit
electric field.
Electrochemical pump – A device to extract or enrich a gas in a gaseous mixture in a
container of freely circulating. Schematically, it consists of a solid electrolyte
that isolates the gas to be enriched or purified. The solid electrolyte is used
as an ionic conductor with the charge carriers being the ions of the chemical
species to be introduced into or extracted from the gas. For example, stabilized
Solid-State Electrochemistry