SIST EN 50324-1:2004

SLOVENSKI SIST EN 50324-1:2004

STANDARD
julij 2004
Piezoelectric properties of ceramic materials and components - Part 1: Terms and
definitions
ICS 01.040.31; 31.140 Referenčna številka
SIST EN 50324-1:2004(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 50324-1
NORME EUROPÉENNE
EUROPÄISCHE NORM May 2002
ICS 31.140
English version
Piezoelectric properties of ceramic materials and components
Part 1: Terms and definitions
Propriétés piézoélectriques des matériaux Piezoelektrische Eigenschaften
et composants en céramique von keramischen Werkstoffen
Partie 1: Termes et définitions und Komponenten
Teil 1: Begriffe
This European Standard was approved by CENELEC on 2001-12-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50324-1:2002 E

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EN 50324-1:2002 – 2 –
Foreword
This European Standard was prepared by the CENELEC BTTF 63-2, Advanced technical ceramics.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50324-1 on
2001-12-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2002-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2004-12-01
This draft European Standard consists of three parts:
Part 1 Terms and definitions
Part 2 Methods of measurement - Low power
Part 3 Methods of measurement - High power
__________

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– 3 – EN 50324-1:2002
Contents
Page
Introduction.4
1 Scope .5
2 Normative references .5
3 Definitions.5
3.1 Ferroelectricity of ceramics .5
3.2 Piezoelectricity of ceramics.7
3.2.1 Piezoelectricity.7
3.2.2 Resonant vibration modes.7
3.2.3 Stability .10
3.3 Classification of materials - Groups of piezoceramics.10

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EN 50324-1:2002 – 4 –
Introduction
The principles underlying the piezoelectricity of ceramics are discussed in IEC 60483 “Guide to
dynamic measurements of piezoelectric ceramics with high electromechanical coupling”. Piezoelectric
ceramics are polycrystalline ferroelectrics mainly based on lead zirconate titanate (Pb(ZrTi)O ), barium
3
titanate (BaTiO ) and lead titanate (PbTiO ). Their piezoelectricity is the result of the preferential
3 3
orientation of polar regions at remanent polarisation. In ceramics, the remanent polarisation is created
by application of a dc electric field to the polycrystalline material. The value of this remanent
polarisation results in the high level of piezoelectric activity in piezoceramics.
Both the direct and inverse piezoelectric effects are utilized. In a variety of applications, piezoelectric
transducers operate at resonance. Static and quasi-static applications complete a wide range of
functions.

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– 5 – EN 50324-1:2002
1 Scope
This European Standard relates to piezoelectric transducer ceramics for application both as
transmitters and receivers in electroacoustics and ultrasonics over a wide frequency range. They are
used for generation and transmission of acoustic signals, for achievement of ultrasonic effects, for
transmission of signals in communication electronics, for sensors and actuators and for generation of
high voltages in ignition devices.
Piezoelectric ceramics can be manufactured in a wide variety of shapes and sizes. Commonly used
shapes include discs, rectangular plates, bars, tubes, cylinders and hemispheres as well as bending
elements (circular and rectangular), sandwiches and monolithic multilayers.
Relevant sections of IEC 60302 “Standard definitions and methods of measurement for piezoelectric
vibrators operating over the frequency range up to 30 MHz” and IEC 60642 “Piezoelectric ceramic
resonators and resonator units for frequency control and selection” have been taken into consideration
when drafting this standard.
2 Normative references
This European Standard incorporates, by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references, the latest edition of the publication referred to applies (including amendments).
IEC 60302 Standard definitions and methods of measurement for piezoelectric vibrators
operating over the frequency range up to 30 MHz
IEC 60483 Guide to dynamic measurements of piezoelectric ceramics with high
electromechanical coupling
IEC 60642 Piezoelectric ceramic resonators and resonator units for frequency control and
selection - Chapter I: Standard values and conditions - Chapter II: Measuring and test
conditions
3 Definitions
The fundamental parameters of the equivalent electric circuit of a piezoelectric resonator are defined
in IEC 60302 and, additionally, IEC 60642 defines terms commonly used to characterize
piezoelectrics. The additional terms defined in this standard describe the properties and performance
parameters of piezoelectric ceramics.
3.1 Ferroelectricity of ceramics
3.1.1
ferroelectric ceramic
non-linear spontaneously polarised ceramics, generally with a high level of permittivity, exhibit
hysteresis in the variation of the dielectric polarization as a function of electric field strength and
temperature dependence of the permittivity (see “Curie temperature”). Ferroelectric ceramics become
piezoelectric by the induced alignment of dipoles, a process generally referred to as poling
To create the macroscopic piezoelectric effect, the polar axes of dipole regions (domains) in
crystallites of ferroelectric ceramics must be aligned. This requires the application of a high dc field at
determined conditions of temperature and time. The poled ceramic has a remanent polarization P
r
which is necessary for piezoelectric activity.

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EN 50324-1:2002 – 6 –
3.1.2
anisotropy
Figure 1 defines the crystallographic axes, as described for the elasto-piezoelectric-dielectric-matrix in
IEC 60483, Table 1. The dielectric, elastic, and piezoelectric properties of poled ferroelectric ceramics
depend on the direction of excitation and piezoelectric action with respect to the direction of remanent
polarization
3.1.3
Curie temperature ϑ
C
this temperature corresponds to the maximum permittivity of ferroelectric ceramics. Ceramics are not
piezoelectric above the Curie temperature
3.1.4
T S
permittivity ε ; ε
ij ij
after poling dielectric anisotropy is present (see Figure 1) and the permittivity may be: “free”
T S
permittivity ε measured well below resonant frequencies; or “clamped” permittivity ε measured far
ij ij
above resonant frequencies
3.1.5
(relative) dielectric permittivity, ε
ratio of (absolute) permittivity ε to the permittivity of free space
ij
-12
ε = 8,854 × 10 F/m,
0
T T T T
/
ε = ε ε ; ε = ε /ε
3r 33 0 1r 11 0
3.1.6
dielectric dissipation factor tan δ
ratio of resistive power (dielectric power loss) to reactive wattless power at sine-wave voltage of
determined frequency; for piezoceramics measured well below the lowest resonant frequency usually
at 1 kHz, together with free capacitance
3.1.7
T
free capacitance C
capacitance of a piezoelectric device, measured well below the lowest resonant frequency (see “free”
permittivity) usually at 1 kHz
3.1.8
S
clamped capacitance C
capacitance of a piezoelectric device, measured far above the resonant frequency (see “clamped”
permittivity)
3.1.9
poling
procedure for creating a macroscopic piezoelectric effect by aligning the polar axes of dipole regions
(domains) in crystallites of ferroelectric ceramic under high electric dc field. The poled ceramic has a
remanent polarisation needed for piezoelectricity
3.1.10
remanent polarisation P
r
macroscopic dipole moment of ferroelectric ceramic after poling

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– 7 – EN 50324-1:2002
3.2 Piezoelectricity of ceramics
3.2.1 Piezoelectricity
Piezoelectricity can be understood as the coupling of elastic and dielectric properties of a solid
exhibiting linear dependence of either
- a mechanical load generating a charge, dependent upon the magnitude and direction of
the load (direct piezoelectric effect), or
- an electric field generating a deformation, dependent upon the strength and direction of
the electric field (inverse piezoelectric effect).
3.2.1.1
electromechanical coupling factor k
defined by the square root of the ratio of the mutual elasto-dielectric energy density squared to the
product of the stored elastic and dielectric energy densities; defined for different boundary conditions,
and a combination of elastic, dielectric, and piezoelectric constants. See also (material) coupling
factors for different vibration modes and effective coupling factors respectively
3.2.1.2
piezoelectric charge constant d
ij
also: piezoelectric deformation constant
couples the electric displacement with the mechanical stress and the strain with the electric field
strength respectively. For piezoceramics there are three constants d , d , d independent of each
33 31 15
other
3.2.1.3
piezoelectric voltage constant g
ij
also: strain constant
couples the electric field strength with the mechanical stress and the strain with the electric
displacement. For piezoceramics there are three constants g g , g independent of each other
33, 31 15
3.2.1.4
piezoelectric component
one or more piezoelectric parts made from poled ferroelectric ceramic (piezoceramic), used for
mechano-electrical or electro-mechanical conversion of energy or for signal processing
3.2.1.5
piezoelectric transducer
piezoelectric part made from poled ferroelectric ceramic (piezoceramic), used for mechano-electrical
or electro-mechanical conversion of energy. In the case of electro-mechanical conversion of energy
(see inverse piezoelectric effect) the piezoelectric solid will be excited to forced vibrations or to self-
excited (resonant) vibrations (see vibration modes)
3.2.2 Resonant vibration modes
3.2.2.1
fundamental vibration mode (see Figure 2)
vibration at the lowest resonance frequency of a given vibration mode
3.2.2.2
overtone
vibration (resonance) excited above the fundamental vibration of a given vibration mode

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EN 50324-1:2002 – 8 –
3.2.2.3
thickness vibration (see Figure 2c)
appears in thin, axially poled, piezoceramic plates with lateral dimensions much larger than those in
the vibration direction. In the case of thickness vibrations all deformations perpendicular to the
vibration direction are zero (see stiffened vibration mode)
3.2.2.4
thickness coupling factor k
t
static electromechanical coupling factor of the thickness extension vibration
3.2.2.5
radial vibration (see Figure 2b)
vibr
...