ISO 11894-1:2013

INTERNATIONAL ISO
STANDARD 11894-1
First edition
2013-04-01
Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test
method for conductivity measurement
of ion-conductive fine ceramics —
Part 1:
Oxide-ion-conducting solid electrolytes
Céramiques techniques — Méthode d’essai pour le mesurage de la
conductivité des céramiques techniques conductrices d’ions —
Partie 1: Électrolytes solides conducteurs d’ions oxydes
Reference number
©
ISO 2013
© ISO 2013
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Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Test piece . 3
5.1 Shape and dimensions . 3
5.2 Surface roughness . 3
5.3 Density . 3
5.4 Electrodes . 3
5.5 Number of test piece . 4
6 Test procedure . 4
6.1 Measurement of cross-sectional area of a test-piece and the distance between
voltage terminals . 4
6.2 Conditions of testing . 4
6.3 Heating of a test piece . 4
6.4 Method for measurement . 4
6.5 Measurement system. 5
6.6 AC impedance meter . 6
6.7 Lead wires . 6
6.8 Preparation for measurement . 7
7 Measurement . 7
8 Calculation of oxide ion conductivity . 7
9 Expression of oxide ion conductivity . 8
9.1 Oxide ion conductivity . 8
9.2 The expression of oxide ion conductivity . 8
10 Test report . 8
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 11894-1 was prepared by Technical Committee ISO/TC 206, Fine ceramics.
ISO 11894 consists of the following parts, under the general title Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test method for conductivity measurement of ion-conductive fine ceramics:
— Part 1: Oxide-ion-conducting solid electrolytes
iv © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 11894-1:2013(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for conductivity measurement of
ion-conductive fine ceramics —
Part 1:
Oxide-ion-conducting solid electrolytes
1 Scope
This International Standard describes a test method for the determination of ionic conductivity of oxide-ion-
conducting solid electrolytes by the 4-terminal method with alternating current (AC 4-terminal method).
This International Standard applies to solid electrolytes which have oxide ionic transference numbers
−1
higher than 0,99. The applicable conductivity range shall be 1 to 1,000 S m .
Values expressed in this International Standard are in accordance with the International System of
Units (SI).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 80000-1, Quantities and units — Part 0: General
ISO 554, Standard atmospheres for conditioning and/or testing — Specifications
ISO 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment: Micrometers for
external measurements — Design and metrological characteristics
ISO 3599, Vernier callipers reading to 0,1 and 0,05 mm
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions
and surface texture parameters
ISO 6906, Vernier callipers reading to 0,02 mm
ISO 14704, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for flexural
strength of monolithic ceramics at room temperature
ISO 15165, Fine ceramics (advanced ceramics, advanced technical ceramics) — Classification system
ISO 18754, Fine ceramics (advanced ceramics, advanced technical ceramics) — Determination of density
and apparent porosity
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
ionic conduction
electrical conduction where ions carry the electrical charges
3.2
electronic conduction
electrical conduction where electrons (or holes) carry the electrical charges
3.3
ionic transference number
ratio of ionic conductivity relative to total conductivity, which is the sum of ionic conductivity and
electronic (hole) conductivity
Note 1 to entry: The region in which an ionic transference number is higher than 0,5 is defined as the ion
conduction region, and the region in which an ionic transference number is higher than 0,99 is defined as the
electrolytic conduction region.
3.4
oxide ion conductor
a substance whose electrical conduction is primarily governed by ionic conduction of oxide ion
Note 1 to entry: In this standard, the term indicates an oxide solid electrolyte with an oxide ion transference
number higher than 0,99.
3.5
AC 4-terminal method
method for measuring electrical conductivity using AC (Figure 1)
Note 1 to entry: In this method, four electrodes are attached onto a test piece. The two outer electrodes which are
called current terminals supply AC to the test piece. The two inner electrodes which are called voltage terminals
measure the voltage. The electrical conductivity is determined with the applied current, the voltage measured
and the geometry of the test piece.
3.6
reversible electrode
electrode where the ionic species acting as the charge carrier can be injected into or removed from the
test piece rapidly enough to give a negligibly small polarization at a supplied current
3.7
Bode diagram
diagram showing the complex impedance of materials by plotting the logarithm of the absolute value of
impedance and the phase of impedance on the ordinate as a function of the logarithm of the frequency
on the abscissa
3.8
common mode voltage
in an impedance measurement using an AC 4-terminal method, the voltages generated between Hp and
Lc, and between Lp and Lc, voltages which have the same amplitude and the same phase
Note 1 to entry: In the measurement described in this standard, this voltage corresponds to the voltage between
the Lp-Lc terminals in Figure 2.
4 Symbols
The symbols used throughout this International Standard and their designations are given in Table 1.
2 © ISO 2013 – All rights reserved

Table 1 — Symbols
Symbol Unit Definition
−1
σ S m Ionic conductivity
L m Distance between voltage terminals
R Ω Effective resistance value
A m Test-piece cross-sectional area
Z Ω Impedance
5 Test piece
5.1 Shape and dimensions
A test piece should be prepared by cutting from a commercial product or a laboratory-made specimen
which is fabricated under the similar conditions as the commercial product. The shape and dimensions
should be in the dimensions of 4 mm x 3 mm x 36 mm or larger, typically 4 mm x 3 mm x 40 mm.
Rounding of the edge, or chamfering is not necessary.
If the test piece mentioned above cannot be made, the shape and dimensions of the test piece shall be in
accordance with the agreement between the parties involved.
5.2 Surface roughness
Surface roughness (Ra) of the test piece should be less than 0,20 μm. In the other cases out of this
condition, the surface roughness shall be reported.
5.3 Density
Bulk density of the test piece shall be measured in accordance with ISO 18754.
5.4 Electrodes
5.4.1 Configuration of electrodes
All 4 electrodes on a test piece, especially the current terminals (hc and lc in Figure 2) shall possess
high reversibility for the conductive oxide ion. The voltage terminals (hp and lp in Figure 2) shall be
fabricated with a spacing of 20 mm in the centre of the test-piece. The width of a terminal should be as
narrow as possible and shall be less than 2 mm. Current terminals shall be placed at least 5 mm away
from voltage terminals, and should be fabricated on both edges of the test piece with a wide area.
5.4.2 Preparation of electrodes
The electrodes for electro-active substances of gaseous species such as oxygen shall possess the porosity
to supply them at the electrode/electrolyte interface.
The electrode layer can be fabricated by one of the following methods of applying/firing conductive
paste, sputtering or vapor deposition. Platinum or silver should
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