INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025
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Effect of Mn and Sb Doping on Electromechanical Coupling
Coefficient and Mechanical Quality Factor of PZT Piezoelectric
Ceramics
SonGuk Pak1, ChenNam Kim2, HyonGyu Pak3, NamChol Yu1*
1Kim Chaek University of Technology, Pyongyang, Democratic People’s Republic of Korea
2University of Science, Pyongyang, Democratic People’s Republic of Korea
3RiGyeSun University of Education, North Huanghae, Democratic People’s Republic of Korea
*Corresponding Author
DOI: https://doi.org/10.51584/IJRIAS.2025.1010000011
Received: 18 Aug 2025; Accepted: 24 Aug 2025; Published: 28 October 2025
ABSTRACT
Introduction: The study of Pb(Zr1-x, Tix)O3 ceramics is growing due to their wide use as piezoelectric
materials. PZT piezoelectric ceramics are a solid solution of ferroelectric PT(PbTiO3) with Curie temperature
490 °C and antiferroelectric PZ(PbZrO3) with Curie temperature 230 °C. To increase the electromechanical
coupling coefficient (kp) and mechanical quality factor (Qm) of PZT piezoelectric ceramics, Mn and Sb
dopants were added.
Materials and Methods: The composition of PZT piezoelectric ceramics was Pb (Zr0.53Ti0.47) to keep them near
the phase boundary and manganese and antimony were added as dopants. The powders were synthesized at 650
°C by sol gel method and sintered at 1150 °C.
Results: The variation of kp and the Qm of piezoelectric ceramics were measured by varying the Mn and Sb
doping ratios. The effect of manganese and antimony dopants on the relative permittivity (εr), piezoelectric
strain coefficient (d33) and density of piezoelectric ceramics was also analyzed.
Discussion: Mn2+ion acts as acceptor ion and creates oxygen vacancies in the perovskite structure, resulting in
shrinkage and deformation of the crystalline unit cell. Kp, Qm, and d33 gradually increased with increasing
doping amount and then decreased again. Then the doping amount was near X = 0.03, the characteristic values
had a maximum.
Conclusion: Considering the variation of K p and Q m with Mn and Sb addition ratio, the electromechanical
coupling coefficient and Q-factor simultaneously reached high values when the Mn content was 30-35% and the
Sb content was 65-70%. Therefore, we set the ratio of manganese to antimony 3:7. The analysis of the
relationship between doping and piezoelectric properties shows that the piezoelectric properties are maximized,
INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025
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Page 166
and the optimum doping is X = 0.03. The electromechanical coupling coefficient and Q-factor were 0.67 and
2900, respectively. The addition of manganese and antimony simultaneously increased the electromechanical
coupling coefficient and the quality factor. However, the addition of manganese can increase the
electromechanical coupling coefficient, but it has not yet reached enough quality factor values due to its
tendency to decrease the quality factor.
Keywords: Mn; Sb; Electromechanical coupling coefficient; Mechanical quality factor; PZT piezoelectric
ceramics
INTRODUCTION
The study of Pb(Zr1-x, Tix)O3 ceramics is growing due to their wide use as piezoelectric materials. PZT
piezoelectric ceramics are a solid solution of ferroelectric PT(PbTiO3) with Curie temperature 490 °C and
antiferroelectric PZ(PbZrO3) with Curie temperature 230 °C. The properties of PZT piezoceramics depend
greatly on the ratio of titanium and zirconium, and the advantages of good control of the ratio of titanium and
zirconium can be easily placed near the phase boundary even at room temperature [1-4]. With the increasing
application of PZT piezoceramics, various methods have been investigated to control the properties of PZT
piezoceramics. In particular, we focus our research on the control of the properties of PZT ceramics by the
addition of various dopants. [11, 12] When PZT piezoelectric ceramics are used as underwater acoustic
transducers, high value of Kp, Qm, and hydrostatic voltage coefficient gh (=dh/εr) are required. The addition of
manganese to PZT piezoelectric ceramics can reduce the εr and increase the dh, thereby increasing the gh. It
also reduces the dielectric loss and increases the value of Qm. [7-9]
However, the addition of manganese tends to increase the gh and Qm while decreasing the kp. The research on
simultaneous enhancement of the kp and the Qm of PZT piezoelectric ceramics by the addition of manganese
and antimony is very scarce. In this work, we investigated the effect of the Mn and Sb dopants on the kp, Qm
and gh of PZT piezoelectric ceramics.
Experimental procedure
Synthesis of powders by sol-gel process
The metal salts containing Zr, Ti, Pb, Mn and Sb ions were dissolved in solvent to obtain a homogeneous sol and
then the PMSZT powder was synthesized by sol- gel method. The raw materials are lead acetate, manganese
acetate, antimony chloride, titanium chloride and zirconium chloride. The reaction was carried out by adding
18.4 ml of titanium chloride to a reactor with isopropyl alcohol C3H7OH. Ammonia hydroxide solution was
slowly added, reacted at 20℃.
TiCl₄ +4C₃H₇0H + 4NH₄0H → Ti(C3H7O)4+4NH4Cl + 4H2O (1)
In this way, 24 g of ZrCl4 and 0.97 g of SbCl3 are dissolved in C3H7O to synthesize Zr(C3H7O)4 and
Sb(C3H7O)3, respectively. Heat for 2 h at 75 °C to make Pb(CH3COO)2•3H2O and Mn(CH3COO)2•4H2O
anhydrous crystals, add 65 g of lead acetate and 0.32 g of manganese acetate to acetic acid and stir in a magnetic
stirrer for 1 h at 50 °C. Then lead acetate and manganese acetate dissolve in acetic acid and transform into a
INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
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transparent liquid with a weak viscosity. Meanwhile, Zr(C3H7O)4, Ti(C3H7O)4 and Sb(C3H7O)3 were added to
the CH3CH2OH solution and stirred for 1 h at room temperature. The two solutions prepared above were mixed
and stirred for another 1 h at 50 °C. As a stabilizer, about 5% acetylacetone is added. oleic acid
(CH3(CH2)7CH=CH(CH2)7COOH) is added as surfactant by 3 wt%. After evaporate the water, the yellow sol
was obtained. It was dried at 50 °C for 2 days to obtain the powder. The obtained powder was sintered at 650 °C
for 5 h to remove organic matter and obtain PMSZT (Pb(Zr0.53Ti0.47)0.97(Mn0.3Sb0.7)0.03O3) nanopowder.
Fig. 1. XRD of PMSZT powder.
Fig. 2. SEM image of PMSZT nanopowder
Sintering process
The powder was added 3 wt% of PVA solution as a binder [5]. The mixture was made into a disk with a diameter
of 25 mm and a thickness of 1.5 mm at a pressure of 100 MPa. As can be seen in Fig. 3, the sintering temperature
was initially raised to 120 °C with a rate of temperature rise of 0.5 °C/min and kept for 1 h to release the moisture.
Then, sintering was carried out at 500 °C for 3 h to remove organic matter [6]. After sintering at 1150 °C for 2 h,
it was cooled to room temperature.
Fig. 3. Sintering process temperature curve
INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
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The sintered samples were coated with silver paste after surface grinding and heated at 550 °C for 20 min to coat
the silver electrode. Then, the samples were polished in 120 °C silicone oil for 5 min with an 18 kV/cm DC
electric field and aged for 24 h at room temperature. The piezoelectric strain coefficient d33 was measured by a
piezoelectric coefficient measuring device. The resonant frequency fr, antiresonant frequency fa and permittivity
were measured by an impedance bridge.
RESULTS AND DISCUSSION
Effect of mixing ratio of Mn and Sb
The variation of kp and Qm factor was measured by varying the ratio of Mn to Sb. The results are shown in Fig.
4.
Fig. 4. Variation of Kp and Qm with Mn and Sb addition ratio.
Manganese has different valence states of divalent, tetravalent and seven valent, because it has valence
variability. The crystal structure of PMSZT also varies with the molar percentage of Mn. Mn2+ion is easily
substituted for the sites where Ti4+ ions with ionic radius of 0.078 nm and Zr4+ ions with ionic radius of 0.082 nm
are present because the ionic radius is 0.067 nm. Mn2+ion acts as acceptor ion and creates oxygen vacancies in
the perovskite structure, resulting in shrinkage and deformation of the crystalline unit cell. This leads to a
decrease in the relativity permittivity and an increase in the value of the Qm. Antimony is present in Sb3+ and
Sb5+ forms, Sb3+ ions (0.09 nm) displace Pb2+ ions (0.126 nm) and Sb5+ ions (0.064 nm) displace Ti4+ ions (0.078
nm) and Zr4+ ions (0.082 nm). The valence state of Sb3+ ions is higher than that of Pb2+ ions, and the valence state
of Sb5+ ions is higher than that of Ti4+ and Zr4+ ions, which leads to an excess positive charge in the crystal lattice.
This leads to lead vacancies to maintain the electroneutral condition. On the one hand, the lattice distortion due
to the difference in radius and the lattice distortion due to the vacancy of lead are introduced. This leads to a
lowering of the potential barrier between the dipole moments and facilitates the movement of the dipoles. Then,
the number of spontaneous polarizations aligned in the direction of the electric field increases and the
piezoelectric properties improve. This is the softening effect that is obtained when antimony is added.
To observe the change in properties with doping amount, samples with doping amounts X = 0.01, 0.02, 0.03,
0.04, and 0.05 were prepared.
First, the change in density with X was measured by Archimedes method. The density change was measured to a
maximum of 7.7 g/cm at X = 0.01, and the density decreased with increasing X, with a minimum of 7.54 g/cm at
INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
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X = 0.05. Then, the changes of kp, Qm, d33 were measured. The kp, εr and Qm are expressed by Eqs. (2), (3), (4).
2
22
2 265.1
a
ra
p
f
ff
k
(2)
Here, fr is the resonant frequency, fa is the antiresonant frequency.
S
tc
r
(3)
Here, C is the capacitance at 1 kHz, t is the thickness of the sample, and S is the electrode area.
rar
a
ra
r
m
ffCZ
f
ff
CZ
Q
42
1
2
22
(4)
where Zr is the impedance of the sample.
Fig. 5. Variation of relative permittivity with doping amount.
Fig. 6. Variation of characteristic parameters with doping amount.
Fig. 5 shows the variation curve of relative permittivity with doping amount. Fig. 6 shows the variation of kp,
Qm and d33 with doping amount. As can be seen, Kp, Qm, and d33 gradually increased with increasing doping
amount and then decreased again. Then the doping amount was near X = 0.03, the characteristic values had a
INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025
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maximum. When the doping amount is too high, they will be overdoped, and they will aggregate at the grain
boundaries, increasing the grain boundaries and decreasing the grain size. This increases the energy consumption
when an external electric field is applied, resulting in an increase in dielectric loss. Also, Kp decreases with
decreasing d33 due to the buffering action caused by the geometric deformation and stress.
CONCLUSIONS
Considering the variation of K p and Q m with Mn and Sb addition ratio, the electromechanical coupling
coefficient and Q-factor simultaneously reached high values when the Mn content was 30-35% and the Sb
content was 65-70%. Therefore, we set the ratio of manganese to antimony 3:7. The analysis of the relationship
between doping and piezoelectric properties shows that the piezoelectric properties are maximized, and the
optimum doping is X = 0.03. The electromechanical coupling coefficient and Q-factor were 0.67 and 2900,
respectively. The addition of manganese and antimony simultaneously increased the electromechanical coupling
coefficient and the quality factor. However, the addition of manganese can increase the electromechanical
coupling coefficient, but it has not yet reached enough quality factor values due to its tendency to decrease the
quality factor. Future work is expected to focus on finding impurities that do not interconnect the
electromechanical coupling coefficient and the Q-factor.
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