Dielectric Properties Of Pb Research Articles

Effect of Milling on Dielectric Properties of PZT

In this study, we investigated the impact of high-energy milling on the structural and dielectric properties of Pb[Zr(1-x)Tix ]O3 [PZT] ceramics synthesized using the solid-state reaction process. The sample was milled for 2, 4 & 6 hours using a high-energy ball milling machine. The unit cell structure for all of the samples was observed to be monoclinic, according to x-ray diffraction measurements (space group: C1m1). A significant reduction in crystallite size was observed, from 132 nm to 46 nm after 6 hours of milling. The dielectric study indicated a classical ferroelectric type behaviour for the un-milled sample and diffused phase transition for all milled samples. However dielectric constant dropped from 940 to 487 after 6 hours of milling.

Effect of different top electrodes on dielectric properties of Pb0.3Sr0.7TiO3thin film

The PST thin films with different top electrodes were prepared by magnetron sputtering and Sol-gel, respectively. The effects of different top electrodes on Dielectric and Tunable Properties of the films were studied. It is found that the comprehensive properties of the PST films can be improved by using suitable top electrodes. When the dielectric tuning amount of PST thin films using Au/Cr dielectric tuning value is 71.4%, the dielectric loss is 0.02004, and the figure of merit (FOM) is 35.7, which has optimal dielectric properties. At the same time, the purpose of replacing precious metals (Au) with cheap metals (Cu) is realized.

Dielectric Properties of Pb(Fe0.5Nb0.5)O3 (PFN) Material Synthesized by B-site Precursor Method

Abstract: B-site precursor method was employed for the synthesis of Pb(Fe0.5Nb0.5)O3 (PFN) Ceramic material. Formation of Perovskite was confirmed by XRD. Study of electrical and dielectric properties were carried out. The increase in dielectric loss and decrease in ac resistivity was observed at higher temperature. Keywords: Perovskite, XRD, B-site precursor, AC conductivity, Dielectric constant.

Structural and dielectric properties of Pb (Zr 0.52Ti 0.48)1-3x/4Fe x O3 ceramics at 0⩽x⩽0.20 prepared by sol-gel method

In this work, the Pb (Zr 0.52Ti 0.48)1-3x/4Fe x O3 (x=0.0; 0.025; 0.05; 0.075; 0.10; 0.15; 0.20) ceramics were synthesized by using the sol-gel method. X-ray diffraction (XRD), Raman spectra, was used to reach the structural properties of the studied compounds. The XRD patterns registered at room temperature revealed the phase formation of the samples which was confirmed by the Rietveld refinement method which suggests the formation of mixed tetragonal and rhombohedral phases. Raman spectra show that when iron content increases, the intensity of Raman peaks of pure PZT increases. The dielectric properties of Pb (Zr 0.52Ti 0.48)1-3x/4Fe x (PZTFx) materials as a function of temperature are studied and displayed a resonance phenomenon for all samples which is moved to the higher frequencies combined with a decrease in dielectric constant when Fe concentration increase. The variation of the dielectric constant as a function of temperature at low frequencies reveals a shifting of the transition temperature to the lower temperature.

Investigation on diffuse phase transition through Raman and dielectric properties of Pb(Fe0.5Nb0.5)O3 – Pb(Co0.33Nb0.67)O3 solid solutions

We report a series of Pb based multiferroic solid solutions (1-x) Pb(Fe0.5Nb0.5)O3 – (x) Pb(Co0.33Nb0.67)O3 (0.1 ≤ x ≤ 0.5) (shortened as PFCN), synthesized using a single-step solid-state reaction method. The structural, microstructural, Raman, and temperature (301–481 K) dependent dielectric (102–106 Hz) and conductivity properties were thoroughly investigated. The room temperature X-ray diffraction data reveals the monoclinic phase with the Cm space group for all the solid solutions. The atomic-level structural parameters were obtained for all the solid solutions from the Rietveld refinement technique, and it was observed that an increase in the unit cell volume with an increase of PCN content in PFN. The field emission scanning electron microscope images confirm the densely packed, uniform coarse arrangement in all the samples. In x = 0.4 and 0.5, a small amount of porous structure was noticed, indicates the reduction in the densities. Energy-dispersive X-ray spectroscopy reveals the existence of Pb, Fe, Co, Nb, and O elements according to stoichiometry. The temperature-dependent Raman spectra of all the solid solutions show a decrease in the intensity and changes in the spectral line shape of B-localized F1u (~250 cm−1) and BO6 octahedral rotation F1g (~260 cm−1) modes around the characteristic temperature, may be a structural transformation from monoclinic to cubic above Tm. The frequency-dependent ε′ and tanδ reveal the presence of Maxwell-Wagner polarization in the lower frequency. The temperature-dependent ε′ shows the ferroelectric relaxor type diffused phase transition Tm (TC) around ~360 K, ~340 K, ~330 K & ~320 K for x = 0.1, 0.2, 0.3 and 0.4, respectively. The reported Tm (TC) systematically decreases with increasing x due to the lower Tm (TC) of PCN compared to PFN. These results were consistent with the anomalies observed at the vicinity of Tm in the Raman spectra. The frequency-dependent ac-conductivity studies reveal the negative temperature coefficient of resistance behavior and obey Johnscher's power law. For x = 0.1 to 0.4, the hump-like behavior was found in both temperature-dependent tanδ and ac conductivity around the transition temperature related to the reorientation of domains, domain wall motion, dipolar contribution to the ferroelectric materials.

Enhanced piezoelectric and dielectric properties of Pb(Yb1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 crystals by combining alternating and direct current poling

As one of domain engineering methods, alternating current poling (ACP) has been proved a convenient, effective, economical method for the enhancement of the dielectric and piezoelectric properties of relaxor–PbTiO3 (PT) ferroelectric crystals. However, a shortcoming of ACP is that there are some non-rotational domains. To further improve the potential piezoelectric properties of relaxor–PT crystals, a modified poling method, combining alternating and direct current poling (ACP + DCP), was used for improving the piezoelectric properties of Pb(Yb1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3 (PYbN–PMN)–PT ferroelectric crystals. Compared with separate DCP and ACP, the piezoelectric coefficient d33 of [001]-oriented PYbN–PMN–PT crystals increased by 51% and 15% using ACP + DCP, respectively, indicating that applying an appropriate DCP on ACP samples is beneficial to further improve the piezoelectric properties. The domain analysis reveals that the full rotation of polarization, regular domain patterns, and domain boundaries are the key factors for the enhancement of piezoelectric and dielectric properties. We established the relationship between the position of the (300)c peaks, reflecting the degree of the stretch of the lattice, and piezoelectric properties. This work indicates that combining alternating and direct current poling methods is a better poling strategy for enhancing the piezoelectric properties of relaxor–PT ferroelectric crystals compared with separate DCP and ACP methods.

The effect of an AC electric field on the dielectric properties of Pb(Mg1/3Nb2/3)O3 ceramic

The dynamic dielectric response of Pb(Mg1/3Nb2/3 )O3 ceramic was experimentally studied as a function of the EAC amplitude field. An increase in real dielectric permittivity was obtained by increasing the applied electrical field within the investigated temperature range for frequencies below 10 kHz. The temperature of maximum dielectric permittivity and freezing temperature decreased with an increase in E AC. Nonlinear permittivity was studied and found to behave similarly to freezing temperature. A statistical model was used to fit the dielectric dispersion of real dielectric permittivity with temperature and frequency. The results are discussed in terms of different factors’ contributions to dielectric permittivity under different EAC field conditions.

Structure, dielectric and piezoelectric properties of Pb[(Zr0.45,Ti0.5)(Mn0.5,Sb0.5)0.05]O3 ceramics

This study describes structure, dielectric and piezoelectric properties of Pb[(Zr0.45,Ti0.5)(Mn0.5,Sb0.5)0.05]O3 (PZT-PMS) ceramics prepared by conventional mixed-oxide route and sintered at up to 1180?C. The prepared ceramics was characterized by X-ray diffraction and scanning electron microscopy. The piezoelectric constants, dielectric constant, Young?s modulus and electromechanical factors were measured in broad temperature range. The results showed that the PZT-PMS ceramics is composed of tetragonal and rhombohedral phases and has the average grain size of about 1 ?m. The Pb[(Zr0.45,Ti0.5)(Mn0.5,Sb0.5)0.05]O3 ceramics has excellent dielectric and piezoelectric properties for wide practical applications. Thus, planar coupling factor of 0.70, poled dielectric constant of 8215, the Curie temperature of 345?C and dielectric loss of 6% were attained in the PZT-PMS ceramics sintered at 1180?C.

Phase transition behavior of Pb(Hf, Sn, Ti, Nb)O3 ceramics at morphotropic phase boundary

AbstractThe phase transition and dielectric properties of Pb0.988(Hf0.945SnxTi0.03‐xNb0.025)O3 ceramics (0 ≤ x ≤ 0.03, correspondingly abbreviated as H1, H2, H3, and H4) at the morphotropic phase boundary were systematically investigated. X‐ray diffraction results and P‐E hysteresis loops show that the dominate orthorhombic antiferroelectric phase and a small amount of the tetragonal FE phase coexist in Pb0.988(Hf0.945SnxTi0.03‐xNb0.025)O3 ceramics. As the Sn content increases, the antiferroelectricity is significantly enhanced, accompanied with an increased Curie temperature and sharply reduced peak dielectric constant. H1 and H2 experience an irreversible field‐induced AFE‐FE phase transition at the ambient temperature, and the transition from a metastable FE phase to the original AFE phase is observed in H2 when heated to 60°C. H3 and H4 experience an invertible AFE‐FE phase transition, along with an enhanced forward phase switching field EF. Moreover a decreased backward phase switching field EA for H4 is detected as the electric field increases due to the AFE/FE coexistence. These results reveal the unique phase transition characteristics of AFE materials near the phase boundary, which is helpful for better understanding of AFE/FE materials.

Structural stability, phase transition and dielectric properties of Pb(Mg1/2W1/2)1−xMxO3 (M = Zr,Sn, Ti) ceramics

ABSTRACTPb(Mg1/2W1/2)1−xMxO3 (M = Zr,Sn,Ti) ceramics have been prepared by the conventional ceramic process. Their crystallographic, phase transition and dielectric properties have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance analyzer in this paper. The solubility of the tetra-valent cation in Pb(Mg1/2W1/2)1−xMxO3 decreases in the sequence of Ti4+ > Zr4+ > Sn4+. The doping led to the phase transition from orthorhombic antiferroelectric to cubic paraelectric phase, the microscopic nature of which could be attributed to the contraction of Pb-O12 dodecahedron. A definition of the ordering parameter of the cubic phase was deduced to quantitatively evaluate the B-site ordering degree which decreased with the increase in doping concentration. Anti-site disordering of Mg2+ and W6+ occurred in the high-level doping compositions, which led to the relaxor behavior observed in Ti4+-doped series with x = 0.01 composition. Both of the maximum dielectric permittivity and loss in the paraelectric phase increased with the increasing doping concentration.

Dielectric Behavior of PZT/Graphene Oxide Composites

The influence of graphene oxide (GO) using modified Hummer's method on the dielectric properties of Pb (Zr1 − xTix) O3 (PZT) using sol–gel route is investigated. The as‐prepared PZT, GO, and PZT/GO composites are characterized by X‐ray diffraction, field emission scanning electron microscope, and Raman spectroscopy. The dielectric measurements of PZT/GO composites are conducted in frequency ranges from 100 Hz to 1 MHz and from room temperature to 80 °C. The dielectric constants of PZT/GO composites are larger than PZT at a frequency 100 Hz, and the dielectric losses are higher than PZT attributed to the presence of space‐charge polarization near the grain boundary interfaces. The observed experimental profile shows about the existence of grains and grain boundaries as confirmed by the impedance analysis. With the increasing content of GO% in the PZT/GO composite, the remnant polarization is approximately constant and coercive electric fields decreases due to space‐charge effects as obtained from the P–E loop measured at room temperature. The remnant polarization drastically reduces with higher wt% of GO (2 wt%) due to the conducting behavior of the PZT/GO composites. Therefore, the obtained higher dielectric constant of the prepared PZT/GO composites signifies that it may be suitable for various related applications.

Structural, piezoelectric, and dielectric properties of PZT-based ceramics without excess lead oxide

A number of previous research have been done on the excess PbO to improve the material properties of PZT-based ceramics. This study takes a step further by studying the consequences of controlled addition of PbO on the structural, piezoelectric, and dielectric properties of Pb(Zr1-xTix)O3 ceramics (PZT-based ceramics). In order to draw qualitative comparisons between their material properties, pure or undoped PZT [Pb(Zr0.52Ti0.48)O3] and doped PZTs (PSZT [Pb0.95Sr0.05(Zr0.52Ti0.48)O3], PLZT [Pb0.98La0.02(Zr0.52Ti0.48)O3], and PLSZT [Pb0.93La0.02Sr0.05(Zr0.52Ti0.48)O3]) were studied. The compositions were prepared through high-energy ball milling in a way to avoid calcination using controlled addition of PbO. After milling, pellets were formed from the mixtures, which were then sintered at 1150 °C. The phase analysis of the sintered mixtures using XRD technique revealed the formation of a single perovskite phase in all the developed ceramics. All the undoped and doped ceramics have relative density of > 90%. La-doped PZT had the best piezoelectric properties with d33 of 372 pC/N and kp of 0.510; in addition, better dielectric properties, i.e., ɛr of 1269 and tan δ of 0.050, were found. This good performance of the La-doped PZT is related to its high density (7.6 g/cm3) and low porosity (0.154), which was clearly observed in its microstructure.

Structural Properties of Pb(Zr<sub>0.52</sub>Ti<sub>0.38</sub>Li<sub>0.1</sub>)O<sub>3</sub> Prepared via High Planetary Mill

In the present work lead based perovskite ceramic Pb (Zr0.52Ti 0.38Li0.1)O3 was prepared via high planetary mill. The green body was sintered at 850 °C. The effect of 0.1 wt % Li+ addition on the sintering temperature, microstructure and on dielectric properties of Pb (Zr0.52Ti0.48)O3 were investigated. Thermal analysis of ceramic reveals that the PZT can be synthesized at low temperature. XRD diffractrogram shows the presence of secondary phase (lead oxide PbO) in the sample. The maximum dielectric constant was observed at low frequency which was 1163.22 at 20 Hz.

Piezoelectric and dielectric properties of Pb0.93La0.02Sr0.05(Zr0.52Ti0.48)O3 ceramics doped with Li2CO3 at low sintering temperature

Pb0.93La0.02Sr0.05(Zr0.52Ti0.48)O3 (PLSZT) ceramics were successfully doped with various amounts of Li2CO3. The effect of Li2CO3 as sintering aid on crystallization process of PLSZT ceramic was also determined by thermal analysis (TGA/DTA). As the amount of Li2CO3 increased from 0.1 to 1mol%, the sintering temperature was found to decrease from 1150 to 850°C. Li2CO3 addition improved the densification and increased the average grain size. XRD data revealed the formation of single perovskite phase in all compositions. The effects of Li+ doping on the piezoelectric and dielectric properties of PLSZT ceramics were also investigated in which the piezoelectric and dielectric properties were found to be enhanced with the increase in Li+ content. The best piezoelectric and dielectric properties were obtained for 0.7mol% Li2CO3 with ρ=7.421g/cm3, KP=0.46, d33=259 (pC/N), εr=1270, and tan δ=0.0847.

Temperature Dependence of Energy Storage in Pb0.90La0.04Ba0.04[(Zr0.7Sn0.3)0.88Ti0.12]O3 Antiferroelectric Ceramics

The temperature‐dependent energy storage and dielectric properties of Pb0.90La0.04Ba0.04[(Zr0.7Sn0.3)0.88Ti0.12]O3 were investigated in this work. With the phase transition from antiferroelectric to paraelectric induced by temperature rise, the releasable energy density decreases from 0.74 J/cm3 (20°C) to 0.29 J/cm3 (140°C), whereas the discharge efficiency increases from 75.0% to 93.4%. The pulsed discharge current indicates that the stored energy can be released in less than 1 μs. The temperature has little impact on the amplitude of the current but influences the discharge duration time greatly. In addition, with the comprehensive analysis of hysteresis loops, the DC‐bias character of dielectric constant and the discharge current, the transition from strong nonlinearity to linearity of the dielectric along with the phase switching was confirmed. It proves that the vanishment of high‐electric‐field nonlinear polarization contributions causes the declination of releasable energy with the temperature rise.

Dielectric properties of Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 film by aerosol deposition for energy storage applications

Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIMNT) thick films with nano-sized grains and a dense film structure were deposited by an aerosol-deposition (AD) method. Unlike bulk PIMNT crystals, the AD films showed a relatively narrow polarization–electric field hysteresis loop due to the nano-grain size effect. The post-annealed AD films had a large energy density resulting from the increasing dielectric constant and low charge/discharge efficiency due to the larger hysteresis.

The effect of addition of Nd3+ on dielectric properties of Pb[Zr0.45Ti0.45(Zn1/3, Sb2/3)0.1]O3 system

This work aims at, to study the influence of Nd 3+ on the dielectric properties of a ceramics material of general formula: ¶Pb[Zr 0.45 Ti 0 . 45 (Zn 1/3 , Sb 2/3 ) 0.1 ]O 3 and of structure perovskite. ¶The selected samples were prepared by the method of synthesis with solid way. ¶The study of the dielectric properties of the system showed that the values of the permittivity, the resistivity, increase with the addition of Nd +3 1%.

Influence of bismuth additives on the dielectric properties of Pb(Fe2/3W1/3)0.7Ti0.3O3 ceramics

In this study, the effects of bismuth additives are investigated based on the dielectric properties by the empirical law and the order–disorder model for the Pb(Fe2/3W1/3)0.7Ti0.3O3–x wt.% Bi2O3 ceramics. The grain size initially increased and the diffused phase transition property initially decreased at x = 0.25 wt.% and then these properties reversed. In addition, the space charge polarization is weakened and then reinforced when the amount of bismuth additives increases. According to these experimental results and the model fitting results, it is concluded that bismuth additives can induce the random-site 1:1 order and change the dielectric properties from relaxor ferroelectric to normal ferroelectric by substituting bismuth ions for the lead vacancies. Furthermore, excess amounts of bismuth additives impede the grain growth and change the dielectric properties from normal ferroelectric to relaxor ferroelectric.

Poling induced dielectric anomalies in a PZT ceramic

Dielectric properties of Pb0.99375(Zr0.52Ti0.48)0.9875Nb0.0125O3 (PZTN) ceramics were measured during heating and cooling processes before and after poling. A dielectric anomaly from 220 K to 290 K was only observed in poled PZTN samples. The frequency dependence of the ε′′ peaks was fitted using the Vogel–Fulcher law, which indicated that this dielectric anomaly could be associated with the poling induced monoclinic distortion. Meanwhile, the existence of the low-temperature transformation involving rotations of the octahedra was confirmed by the broadening peaks in ε′′–T curves and the variation of slopes in ε′–T curves in both unpoled and poled samples.

Variations of composition and dielectric properties of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal along growth direction

The compositional dependent dielectric properties of [001]-poled Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal are investigated along the [011] growth direction. The variation of Pb(In1/2Nb1/2)O3, Pb(Mg1/3Nb2/3)O3, and PbTiO3 content of crystal boule with a length of 70 mm are found to be around 1.3%, 10.5%, and 9.9%, respectively. The rhombohedral-to-cubic or rhombohedral-to-tetragonal phase transition temperature is more than 120 °C for the composition with rhombohedral phase far away from the morphotropic phase boundary. The phase transition temperature of rhombohedral-to-tetragonal, rhombohedral-to-monoclinic/orthorhombic, and monoclinic/orthorhombic-to-tetragonal move to lower temperature and the tetragonal-to-cubic move to higher temperature along crystal growth direction. The tetragonal phase induced by [001]-poling, composition, and temperature can help to improve the piezoelectric properties and the induced monoclinic/orthorhombic phase can further improve and mainly contribute to the high piezoelectric properties. The phase diagram was established based on the composition and dielectric properties. At room temperature, the rhombohedral-monoclinic/orthorhombic phase boundary was found to be nearly PIN-PMN-0.34PT.