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The effect of simultaneous substitution of La3+ and Fe3+ ions on structural, dielectric, ferroelectric and piezoelectric properties of BaTiO3 was studied. Polycrystalline ceramic samples with composition Ba1-xLaxTi1-xFexO3 with x = 0, 0.005, 0.015 and 0.020 were prepared by the solid-state route and sintered at 1325°C. X-ray diffraction (XRD) analysis confirmed the single phase with tetragonal perovskite structure in all the prepared ceramics. Dielectric constant 'ϵ' and tangent loss 'tanδ' was measured as a function of temperature (25–200°C). The value of ϵ increases with an increase in La and Fe contents. A very small value of tanδ (<4%) was observed. The temperature coefficient of capacitance 'Tcc' was found to be around 10% for all the samples. PE hysteresis loops were recorded at room temperature for all samples. The maximum value of ϵ and piezoelectric coefficient 'd33' was found to be 3735 (at 30°C, 100 kHz) and 140pC/N, respectively for x = 0.020. [ABSTRACT FROM AUTHOR]

High-density polycrystalline ferroelectric ceramics having compositional formula Ba0.70Ca0.30Ti1−xFexO3, BCTF (with x = 0.000, 0.010 and 0.015) were prepared by solid-state reaction route. The samples were sintered at 1325 °C for 4 h. The samples were investigated for structural, dielectric, ferroelectric and magnetic properties. Raman and X-ray diffraction analysis confirms the tetragonal phase in all the samples. It can be observed from the dielectric versus temperature curves that all the prepared compositions showed a diffused phase transition. The Curie temperature was observed to be decreasing from 93 °C to 72 °C with the increase in Fe content. PE hysteresis loops were recorded at different electric fields. Pinched hysteresis loops were observed for all the samples, wherein, the pinching increased with the increase in Fe content. The energy density 'Ed' and efficiency 'η' were calculated from the PE loops. A high value of Ed = 0.15 J/cm3 with an efficiency of 67% was observed for the sample with x = 0.015 at 35 kV/cm. MH hysteresis loops were recorded at room temperature for all the prepared samples. The simultaneous observations of PE and MH hysteresis loops confirm the multiferroicity in the prepared samples. [ABSTRACT FROM AUTHOR]

We report the effect of processing parameters such as (1) uniaxial and (2) isostatic pressings on ferroelectric behavior of lead zirconate titanate (PZT) having Zr/Ti ratio 65/35. The effect of temperature (-125–250 °C) on pinched loop characteristics of uniaxially pressed PZT is also reported. Polycrystalline ceramic samples were synthesized by solid-state reaction technique and sintered at 1250 °C. The density was estimated to be 7.63 and 7.58 g/cc for the uniaxially and isostatically pressed samples, respectively, prepared by conventional ball milling. X-ray diffraction analysis confirmed single phase formation with rhombohedral structure. All samples pressed uniaxially and isostatically showed pinched hysteresis loops at room temperature that disappear at higher temperatures. The remnant polarization (Pr) and coercive field (Eo) for the uniaxially pressed samples become well defined in magnitude and shape at higher measurement temperatures below phase transition temperature (Tc), but at low temperatures a distorted-loop-like structure was observed indicating low polarization properties. The effect of ferroelectric switching cycles on the PZT samples with and without annealing in oxygen is also discussed. [ABSTRACT FROM AUTHOR]

Eu substituted BiFeO 3 (Bi 1− x Eu x FeO 3 ; x =0–0.15) polycrystalline ceramics were synthesized by a solid state reaction method. Rietveld refinement of X-ray diffraction patterns reveals that samples crystallize in R 3 c structure for x ≤0.10 and ( R 3 c + Pn 2 1 a ) phases coexist for x ≥0.12–0.15. The magnetic measurements show weak ferromagnetic nature of Eu substituted BiFeO 3 samples due to ferromagnetic coupling between Eu 3+ and Fe 3+ ions. The remnant magnetization is found to increase from 0.0003 emu/g for x =0.00 to 0.087 emu/g for x =0.15. The gradual change in line shape of electron spin resonance spectra has been attributed to local distortion induced by Eu substitution. UV–visible absorption spectra in the spectral range 1.12–3.5 eV were dominated by two charge transfer transitions and two doubly degenerate d–d transitions. The optical band gap is found to decrease from 2.25 to 2.16 eV with increasing Eu concentration. Improved dielectric properties with enhancement in frequency independent region of dielectric constant and loss have been observed. [ABSTRACT FROM AUTHOR]

Material series with compositional formula BaPbTiZrO (0 ≤ x ≤ 0·20, in steps of 0·05) were prepared by conventional solid state method. All the samples were subjected to X-ray diffraction (XRD) studies and found to be single phase with perovskite structure. SEM measurements were done in order to collect micro-structural information. Different transition temperatures were found to depend on the Pb content. Tetragonality ( c/a) and Curie temperature ( T) increase with increase in lead content x. Dielectric properties were studied as a function of temperature and frequencies. [ABSTRACT FROM AUTHOR]

A polycrystalline sample of Zr-doped barium titanate (BaTiO) was prepared by conventional solid state reaction method. The effect of Zr (0·15) on the structural and microstructural properties of BaTiO was investigated by XRD and SEM. The electrical properties (dielectric, ferroelectric and impedance spectroscopy) were measured in wide range of frequency and temperature. With substitutions of Zr, the structure of BaTiO changes from tetragonal to rhombohedral. Lattice parameters were found to increase with substitution. The room temperature dielectric constant increases from ∼ 1675 to ∼ 10586 and peak dielectric constant value increases from ∼ 13626 to ∼ 21023 with diffuse phase transition. Impedance spectroscopy reveals the formation of grain and grain boundary in the material and found to decrease with increase in temperature. [ABSTRACT FROM AUTHOR]

The composites consisting of Mn doped Ni0.8Zn0.2Fe2O4 and Zr substituted Ba0.9Sr0.10TiO3 (BST) where Zr varies from 0.00 to 0.16 in steps of 0.04 were prepared by conventional solid state reaction route. The existence of both phases was confirmed by the XRD patterns and the lattice parameters for each composition were calculated. The dielectric parameter such as dielectric constant and dielectric loss were measured as a function of frequency and temperature. As we increase the Zr in ferroelectric phase, the dielectric loss of composite samples decreases up to 1% from 8%, and also Tmax decreases towards room temperature. Observation of ferroelectric and magnetic hysteresis loops for all samples confirms the electric and magnetic nature of the samples. [ABSTRACT FROM AUTHOR]

In the present work, we are reporting the effect of Mn doping on the structural, dielectric and ferroelectric properties of Ba0.80Pb0.20Ti0.90Zr0.10O3. Samples were prepared by solid state reaction route. X-ray diffraction analysis confirmed the compositions to be single phase. Dielectric properties were studied as a function of temperature and phase transition temperature (Tc) was determined. Ferroelectric behaviour was studied in detail as a function of temperature. Mn doping was found to improve temperature stability of the material. [ABSTRACT FROM AUTHOR]

Due to its important applications, there has been a great deal of interest in the fabrication as well as in the electrical and ferroelectric properties of barium titanate (BT)-based ceramics. The dielectric and ferroelectric properties of BT depends on the fabrication techniques and compositional modifications. In conventional solid state reaction technique, the main problem in fabrication of ceramics includes contamination from the tearing and wearing of balls and walls of the milling container, time and power consumption. Various attempts has been made in reducing the time and power consumption. Ultrasonic mixing of raw materials to prepare desired material is a method to reduce contamination and time & power consumption. X-ray diffraction confirms the existence of single phase. Comparative study of the dielectric properties shows the better stability of dielectric constant with frequency and temperature in case of barium titanate prepared using ultrasonically mixing. [ABSTRACT FROM AUTHOR]

In this paper we report samarium substituted Ba0.80Pb0.20Ti0.90Zr0.10O3 (BPZT) ceramics. The material series with compositional formula Ba0.80-xSmxPb0.20Ti0.90Zr0.10O3 with x varying from 0 to 0.01 in the steps of 0.0025 was chosen for investigations. The material was synthesized by solid state reaction method. Reacted powders compacted in the form of circular discs were sintered at 1325°C. All the samples were subjected to X-ray analysis and found to be single phase. Dielectric behavior was studied as a function of frequency and temperature and Curie temperature (Tc) was determined. Tc was found to decrease with increasing x. The details are discussed and presented here. [ABSTRACT FROM AUTHOR]

The different sintering techniques have been found to have remarkable effect on the microstructure and electrical properties of ceramics. The two-stage sintering technique has a potential for fabricating highly dense ceramics at low cost. The effect of two-stage sintering on the dielectric and ferroelectric properties of Ba0.80Pb0.20TiO3 ceramics prepared by solid state route were investigated in this study. It has been found that, under suitable two-stage sintering conditions, the dense Ba0.80Pb0.20TiO3 ceramics can be successfully achieved with improved electrical properties. The tetragonality is also found to increase in the samples sintered by the two stage sintering. [ABSTRACT FROM AUTHOR]

Abstract: Ceramic samples of the nominal composition Ba(Zr x Ti1−x )O3 (x =0.15) were synthesized by the solid-state reaction method and the sintering was done in two different atmospheres—air and oxygen. Oxygen sintering resulted in samples with dense microstructures. Low field dielectric measurements showed an increase in the values of dielectric constants over the entire temperature range of measurement, in the oxygen-sintered samples. Similarly, polarization–electric field (P–E) hysteresis measurements indicated a marked increase in the value of remnant polarization in them. [Copyright &y& Elsevier]

Abstract: The dielectric constant (ε r), dielectric loss (tan δ) and strain induced by electric field in lead magnesium niobate–lead titanate (PMN-PT/PMNT) solid solutions in the morphotropic phase boundary (MPB) region at different sintering temperatures have been studied. ε r and tan δ increase, whereas Curie phase transition range decreases with the increase in sintering temperature. Strain levels in the range of 0.07–0.2% were obtained. A high saturated strain% ∼0.19, a high d 33 coefficient ∼320pm/V and a low strain hysteresis% ∼3.5 in PMNT 68/32 composition sintered at 1200°C indicate its suitability for actuator applications. [Copyright &y& Elsevier]

Li0.45Ni0.1Mn0.1Fe2.35O4 ferrite samples were prepared by microwave-sintering (MS) and conventional (CS) techniques. XRD studies have confirmed the single-phase spinel structure of the sample. The lattice constant was found to be 8.334 Å which is lower than that of the conventionally sintered (CS) sample. Upon microwave sintering, improved physical and electrical properties (like density, resistivity etc.) were obtained. A comparative study has been made on the dielectric behavior of samples processed by both techniques. The possible mechanisms are discussed. [ABSTRACT FROM AUTHOR]

In the present paper, we report the effect of Samarium substitution and Niobium doping on the properties of a PZT(52:48). The properties studied are: structural, dielectric and ferroelectric. The samples with chemical formula Pb0.99Sm0.01Zr0.52Ti0.48O3 were prepared by solid-state dry ceramic method. Small amount (0.5 wt%) of Nb2O5 was also added. X-ray diffraction (XRD) analysis showed formation of a single phase with tetragonal structure. Dielectric properties were studied as a function of temperature and frequency. Transition temperature, Tc, was determined from dielectric constant versus temperature plot. The material shows well-defined ferroelectric (PE) hysteresis loop. [ABSTRACT FROM AUTHOR]

Abstract: The magnetic properties, such as initial permeability and hysteresis loop properties of the chromium substituted Li–Sb ferrite system have been investigated. The SEM micrographs reveal the microstructure of the samples. The initial permeability is observed to decrease with the increase of chromium concentration. Frequency variation of permeability indicates that for all samples the resonance peak due to domain wall oscillations is at a frequency above 15MHz. The hysteresis loop parameters have been calculated from the hysteresis loop studies. The magnetic parameters are observed to decrease with higher level of substitution. [Copyright &y& Elsevier]

Morphotropic phase boundary (MPB) compositions of (1-x)PMN-(x)PT system, where x=0.30, 0.32 and 0.34, were prepared in single perovskite phase by the B-site Columbite precursor method. Temperature dependence of dielectric behavior, measured at different frequencies, revealed the transformation of the system from relaxor to normal ferroelectric behavior and decrease in dielectric dispersion near transition temperature (Tc) with the increase in PT content. Appearance of an abnormal hump in the dielectric behavior of PMNT 68/32 composition confirms the MPB nature of the system. Remnant polarization, Pr was found to be ~ 23, 22 and 27 μC/cm2, whereas coercive field, Ec was found to be ~ 3.3, 3.9 and 3.6 kV/cm for PMNT 70/30, 68/32 and 66/34 compositions respectively. Strain versus electric field (S-E) behavior revealed the piezoelectric nature of these compositions with a maximum strain ~ 0.75% at 31 kV/cm applied electric field in PMNT 68/32 composition. Temperature variation of the pyroelectric coefficient, Pi, confirms Tc, as obtained by dielectric measurements. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, different PMNT samples in the MPB range were prepared in single perovskite phase using Columbite technique. After poling, dielectric constant (ε r) of PMNT 70/30 samples decreases and of PMNT 68/32 and PMNT 66/34 samples increases. Polarization vs. electric field (P–E) hysteresis loops of PMNT samples show their ferroelectric nature. Transition temperature (T c) obtained from pyroelectric coefficient () variation with temperature increases with the increase in PT content in PMNT samples near MPB and agrees with T c obtained from the dielectric study. [Copyright &y& Elsevier]

The effect of lanthanum substitution on the structural, dielectric and piezoelectric properties of lead calcium titanate (PCT) ceramics is studied. Samples with compositional formula Pb0.76- x La x Ca0.24Ti0.98Mn0.02O3 (PLCT) ( x &ThickSpace;=&ThickSpace;0–0.08, in steps of 0.02) were prepared by the conventional dry ceramic technique. Phase and structural analysis was carried out using XRD and SEM respectively. X-ray analysis confirmed the formation of single-phase compound with tetragonal crystal structure. Dielectric properties were studied in detail as a function of frequency and temperature. The Curie temperature ( T C) and tetragonality ( c / a ) was found to decrease with increase in lanthanum content. The Curie temperature was also confirmed from the thermal-expansion behaviour of the sintered samples. Piezoelectric coefficients ( d 33, d 31, g 33, g 31, g h, d h, k t and k p) were measured at room temperature. From this study it is found that La 3+ substitution helps in the improvement of electro-mechanical anisotropy. [ABSTRACT FROM AUTHOR]

Dielectric properties such as dielectric constant (ε′) and dielectric loss tangent (tan δ) of Li0.5+xFe2.5-2xSbxO4 ferrites, 0.10≤ x ≤0.30 in steps of 0.05 have been investigated as a function of composition, frequency and temperature. The dielectric constant showed dispersion with frequency in the range of 100 Hz–1 MHz. Peaks were observed in the tan δ versus frequency curves for almost all the samples. The temperature variation of dielectric constant for the different samples was studied at 10 kHz in the temperature range from room temperature to 433 K. Peaks were observed for some of the samples. The peaks were seen to shift towards higher temperature region as the substitution level increases. The mechanisms involved in the processes are discussed in this paper. [ABSTRACT FROM AUTHOR]

The structural and dielectric properties of a PZN-PLZT solid solution were investigated. The formation of a single phase was studied by the addition of PLZT (8/60/40) in the present system. With the increase of PLZT, the content of the pyrochlore phase decreased significantly and PZN ceramics with 100% perovskite phase could be achieved with x>0.6. Dielectric properties were investigated as a function of temperature and frequency. The ferroelectric hysteresis loop shows typical characteristics of ferroelectrics. [ABSTRACT FROM AUTHOR]

Lead magnesium niobate titanate, PMNT 68/32, ceramic was prepared by a sol–gel technique using alkoxide precursors. Perovskite phases with mixed structure (rhombohedral and tetragonal) were identified by X-ray diffraction (XRD). A dense and homogeneous distribution of sub-micron-size grains was obtained from a scanning electron microscopy (SEM) study. The dielectric response showed relaxor behavior of the material with a transition temperature of ~130°C at 1?kHz. The polarization versus electric field ( P – E ) hysteresis loop with a remnant polarization, P r, of ~28?µC/cm 2 and a coercive field, E c, of ~4.2?kV/cm confirmed the ferroelectric nature of the material. The room temperature values of the piezoelectric coefficient, d 33, and the pyroelectric coefficient, p i, were found to be ~300?pC/N and ~56?nC/cm 2 ?K, respectively. The development of high strain with a large hysteresis in the strain versus electric behavior was related to the morphotropic phase boundary (MPB) nature of the material. [ABSTRACT FROM AUTHOR]

The effect of samarium substitution on dielectric and ferroelectric properties of BST is studied. Sample with compositional formula [Ba 0.95 Sr 0.05 ] 1- x /2 Sm x Ti 1- x /2 O 3 , with x varying from 0 to 0.025 in steps of 0.005, were prepared by the conventional dry method. X-ray analysis confirmed the formation of single-phase compound in the tetragonal crystal system. Dielectric properties were studied in detail as a function of frequency and temperature. Variation of dielectric constant with temperature shows a ferroelectric phase transition, and the transition temperature decreases with increasing samarium content. The activation energy for d.c. and a.c. conduction were determined from the variation of conductivity with temperature. [ABSTRACT FROM AUTHOR]

Modified PZT compositions with representative formula Pb0.925−xSmxLa0.075(Zr0.2Ti0.8)0.981O3 were prepared by double sintering ceramic method. Samarium content, x, were varied from 0 to 0.02. Effects of samarium substitution on structural and dielectric properties are reported here. All the samples were subjected to XRD analysis and were found to have single phase with tetragonal structure. The variation in density has been explained by considering the change of the vacancy concentration, which controls the volume diffusion during densification. With increasing x, dielectric constant was found to increase marginally while dielectric loss decreases appreciably. Curie temperature, as determined from dielectric constant vs. temperature plots, is found to decrease with increasing samarium concentration. [Copyright &y& Elsevier]

Abstract: Study on structural, dielectric and ferroelectric properties of Sm substituted BPTNZ system with compositional formula Ba0.80−x Sm x Pb0.20Zr0.10Ti0.90O3+0.5% Nb2O5 by weight, (x=0 to 0.01 in the steps of 0.0025) was done. Conventional solid state method was adopted for the synthesis of the samples. The single phase was confirmed by X-ray diffraction (XRD) analysis. Scanning electron microscopy was done for microstructural analysis. The dielectric properties were measured as a function of temperature and frequency. Ferroelectric P–E loops were recorded for all the samples at room temperature. Piezoelectric parameters such as ‘d 33’ and electromechanical coupling coefficient ‘k p’ were also measured at room temperature for all the samples. The relationship between properties and structure of the prepared ceramics was established and results are discussed here. [Copyright &y& Elsevier]

Abstract: Polycrystalline samples of the nominal composition Pb0.76−x Sm x Ca0.24Ti0.98Mn0.02O3 were prepared using a solid state reaction technique. Single-phase formation was checked through X-ray diffraction. Dielectric properties were studied as a function of frequency and temperature. The transition temperature determined from dielectric constant vs. temperature plots was found to decrease with increasing Samarium substitution. Poling field was optimized to achieve maximum piezoelectric properties. Piezoelectric coefficients e.g. d 33, d 31, g 33, g 31, g h, d h, k t and k p were measured. The experimental results successfully showed that samarium substitution is helpful to obtain a much higher value of thickness electromechanical coupling coefficient, k t (∼57%) while maintaining a smaller planar electromechanical coupling coefficient, k p in PCT ceramics. [Copyright &y& Elsevier]

In the present article, lanthanum substituted modified PZT (Pb,La)(Zr,Ti,Fe,Nb)O 3 , (Zr:Ti=60:40) PLZFNT bulk ceramics were prepared by solid state reaction technique. The concentration of La 3+ was varied from 0 to 1 mol%. X-ray diffraction (XRD) analyses of these samples suggest the formation of good quality and homogeneous single phase pervoskite compounds. Lattice parameters (a & c) were found to decrease with increase in La 3+ concentration. The dielectric properties of PLZFNT were measured using LCR meter as a function of temperature and frequency. It was found that dielectric properties of the samples are highly dependent on the La 3+ content. Room temperature dielectric constant was found to be increased, whereas the Curie temperature decreased with La 3+ content. [ABSTRACT FROM AUTHOR]

• Fe3+ modification was done in BZT-BCT ceramics near MPB. • Diffused phase transition can be observed for all the samples. • The maximum value of ε was found to be 16,000 (at 30 °C, 100 kHz) for x = 0.45. • Maximum value of energy density efficiency was found to be 86% at 20 kV/cm for x = 0.50. Ceramic samples with compositional formula (1-x)BaTi 0.80 Zr 0.20 O 3 -xBa 0.70 Ca 0.30 Ti 0.99 Fe 0.01 O 3 with x = 0.45, 0.50 and 0.55 were prepared by conventional solid state reaction method. The structural analyses were done by X-ray diffraction and Scanning Electron Microscopy. A high value of dielectric constant at room temperature was found for all the samples. PE hysteresis loops were recorded and energy storage efficiency was determined for all the samples. The value of η was found to be around 80% at a small electric field of 20 kV/cm. The results show significant improvement in the properties of the prepared ceramics. [ABSTRACT FROM AUTHOR]

The standard solid state reaction method has been used to synthesize solid solution 0.8Bi 1- x Nd x FeO 3 –0.2PbTiO 3 where x = 0.05, 0.10, 0.15 and 0.20 (BNFPT) x. The effect of Nd3+substitution on magnetic, ferroelectric, dielectric, and structural properties of 0.8BiFeO 3 -0.2PbTiO 3 (BNFPT) x have been studied. The X-Ray Diffraction and Raman study of the samples revealed that the tetragonal structure with P4mm space group and rhombohedral structure with R3c space group exists simultaneously. The SEM study reveals uniform grain scattering. The 0.8BiFeO 3 -0.2PbTiO 3 compound with Nd doping exhibits an increase in dielectric constant and reduce dielectric loss with respect to temperature and frequency. These features make the material as a promising candidate for the development of electronic device. At room temperature, all prepared samples exhibit weak ferro-magnetic behavior. However, a steady increase in residual magnetization was observed at 5 K. The magnetization result was found to be better than that of other rare earth doped BiFeO 3 -PbTiO 3 solid solution. Ferroelectric study of the sample ascertained the pinning effect with low residual polarization in hysteresis loops. The reduction of leakage current with Nd doping is promising candidate for range of applications. • Nd doped BiFeO 3 - PbTiO 3 solid solution with varying Nd compositions have been prepared by solid state reaction method. • The X-Ray Diffraction and Raman study revealed the coexistence of tetragonal and rhombohedral structures simultaneously. • Nd doping exhibits an increase in dielectric constant and reduce dielectric loss with respect to temperature and frequency. An anomaly in the dielectric constant (ε) is a signature of magnetoelectric (ME) coupling. • The magnetic properties were greatly enhanced with the increasing Nd content. • The reduction of leakage current with Nd doping is promising candidate for range of applications. [ABSTRACT FROM AUTHOR]

Abstract: Material series with compositional formula Ba0.9Sr0.1Zr x Ti1−x O3 (BSZT) were prepared by conventional solid state reaction route. XRD pattern shows that all the samples are well crystallized into perovskite structure. Tetragonality was found to decrease with increase in Zr content. Effect of substitution of Zr on dielectric constant, tangent loss and nature of transition temperature is discussed in the present paper. [Copyright &y& Elsevier]

Abstract: Barium titanate is one of the most studied ferroelectric materials which has been used in various forms, e.g. bulk, thin and thick films, powder, in a number of applications. In order to achieve a material with desired properties, it is modified with suitable substituents. Most common substituents have been strontium, calcium and zirconium. Here, we report studies on lead and zirconium substituted barium titanate. The material series with compositional formula Ba0.80Pb0.20Ti1−x Zr x O3, with x varying from 0 to 0.1, was chosen for investigations. The material was synthesized by solid-state reaction method. Reacted powders compacted in the form of circular discs were sintered at 1300°C. All the samples were subjected to X-ray diffraction (XRD) analysis and found to have single phase perovskite structure. Dielectric behavior was studied as a function of frequency and temperature. Curie temperature (T c) was found to decrease with increasing x. [Copyright &y& Elsevier]

Abstract: The influence of Samarium substitution on the dielectric properties of modified PZT composition with representative formula [Pb1−x Sm x Zr0.588Ti0.392Fe0.01Nb0.01O3] system is reported. Samarium (Sm) was varied from 0 to 0.01/FU in the present system in a step of 0.0025. The samples were prepared by the traditional solid state reaction process. XRD analysis showed all the samples to be single phase with tetragonal structure. Dielectric properties were studied in detail as a function of frequency and temperature (from room temperature (RT) 30 to 400°C). All compositions show phase transition and the transition temperature (T C) is found to decrease with increase in Sm substitution. Room temperature dielectric constant shows an increasing trend while loss improves with Sm doping. [Copyright &y& Elsevier]

Abstract: Here, we report dielectric behaviour of lanthanum substituted Ba0.80Pb0.20Ti0.90Zr0.10O3 (BPZT) ceramics. The material series with compositional formula Ba0.80− x La x Pb0.20Ti0.90Zr0.10O3 (BLPZT) with x varying from 0 to 0.01 in the steps of 0.0025 was chosen for investigations. The material was synthesized by solid state reaction method. Reacted powder compacted in form of circular discs were sintered at 1325°C. All the samples were subjected to X-ray diffraction (XRD) analysis and found to be single phase. Dielectric behaviour was studied as a function of frequency and temperature and Curie temperature (T c) was determined. T c was found to decrease with increasing x. The details are discussed and presented in this paper. [Copyright &y& Elsevier]

Abstract: The dielectric properties of Li0.4−0.5x Zn0.2Co x Fe2.4−0.5x O4 ferrites with varying from 0.0 to 0.1 in steps of 0.02 synthesized by the citrate precursor method have been investigated as a function of composition and temperature. Room temperature dielectric constant studied at 1 kHz showed a decrease with addition of Co2+ ions. The variation of dielectric constant with temperature was studied at different frequencies, and an increase was observed as the temperature rises. For certain composition, at particular frequency resonance maxima could be observed in the dielectric constant versus temperature curve. The possible mechanisms responsible for the above behaviour are explained. [Copyright &y& Elsevier]