PIEZOCERAMIC MATERIALS OF THE LZT
(LEAD ZIRCONATE-TITANATE) SYSTEM PREPARED
BY SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS
I. L. Trubnikov
and S. N. Svirskaya
Translated from Ogneupory i Tekhnicheskaya Keramika, No. 4, pp. 25 – 29, April, 2002.
Powdered products for fabricating piezoceramic materials of the LZT system are prepared by self-propagating
high-temperature synthesis. Lead dioxide PbO
as an oxidizer and metallic titanium and sucrose as reducers
The ability to remain infinitely long in a metastable state
is a specific feature of solid matter. Kinetically stable under
normal conditions, solid-state phases exhibit an enhanced re-
activity when subjected to thermal, impact and other external
factors. For preparing these active materials, mechanical or
mechanochemical activation of powders or various nonequi-
librium synthetic methods that facilitate conventional or re-
active sintering have been used in ceramic technology.
Of the techniques used for creating dissipative structur-
ing in materials at par with crystallization (plasma chemical,
laser-based, or explosive synthesis ), self-propagating
high-temperature synthesis (SHS) has gained wide accep
tance . Until now, the major efforts of synthetic chemists
and materials scientists were mainly focused on the produc
tion of powdered refractory oxygen-free compounds for en
gineering ceramic applications. The synthesis of oxides is a
relatively new field in SHS practice. Presumably, this is ex
plained by the prevailing opinion that combustion of pure
metals is little effective technologically. However, subse
quent studies [3, 4] have shown the promising potential of
SHS processes for preparation of functional high-density ce
ramic materials of complex composition.
Our goal in this work was to study an oxide ceramic ex
hibiting piezoelectric properties.
MATERIALS AND TECHNIQUES
The reagents used in this study and their quality were:
titanium oxide TiO
— reagent grade, TU-10727–87
titanium powder Ti — reagent grade, TU-14-1-3086–80
zirconium oxide ZrO
— reagent grade, 1st grade, State
Standard GOST 21907–76
lead oxide PbO — analytical grade, GOST 5539–73
lead dioxide PbO
— reagent grade, GOST 4216–78
tungsten oxide WO
— analytical grade, TU 6-09-63–70
cadmium oxide CdO — analytical grade, MRTU
— reagent grade, GOST 5833–54.
The SHS technology for preparing powders involved the
– dosing, disintegration, and mixing of the starting com
– direct synthesis of the material;
– grinding of the material synthesized.
The starting components were weighed into portions
(doses) on an analytical balance with an accuracy of 0.001 g.
Sieve analysis (separation into fractions with a specified par
ticle size) was carried out using sieves with mesh sizes of 50,
100, and 200 mm.
The grinding and mixing of the starting components and
the disintegration of the material synthesized were per
formed by hand using an agate mortar and pestle.
SHS was carried out using reactors that were cylinders
made of conventional steel. Initiation (ignition) of the mix
ture was done by means of a heating resistance element pow
ered at a voltage of 5 – 10 V through an adjustable laboratory
transformer. The combustion time of a mixture was
1 – 3 min depending on the mixture composition. The heat
ing temperature was controlled by means of a platinum-
platinorhodium thermocouple. The synthetic product was
crushed to a particle size greater than 4000 cm
Refractories and Industrial Ceramics Vol. 43, Nos.3–4, 2002
1083-4877/02/0304-0136$27.00 © 2002 Plenum Publishing Corporation
Rostov State University, Rostov, Russia.