Properties Of Barium Titanate Research Articles

Tuning structural, dielectric, and ferroelectric properties of BTO-based ceramics through dual-site substitution

Different strategies for tuning the properties of ferroelectric materials have been employed for advancing electromechanical applications. Among several material synthesis techniques explored, site substitution is an effective approach. The present work focuses on Ba1-xCaxSnyTi1-yO3 (BCST) ceramics prepared by solid-state sintering route with different substitution levels (x = 0, 0.05 and y = 0, 0.09). The impact of site substitution on the properties of Barium Titanate (BTO), phase purity, structural analysis, chemical composition, dielectric, and ferroelectric properties have been studied. An ionic radii difference at A-site and B-site substitution is a key factor to achieve significant changes in physical and structural properties. X-ray diffraction patterns ensure the formation of pure phase perovskite structure in all the compositions. Raman spectroscopy indicates Ca substitution not only occurs at the A-site but also within the oxygen octahedra, adversely affecting the properties. Ca and Sn act as strong grain growth inhibitors, leading to a fine-grained and dense microstructure in BCST. While Ca substitution has a limited impact on the Curie temperature (TC), Sn substitution lowers TC in BST (54 °C) and BCST (50 °C) compared to BTO (126 °C). The Sn substitution results in the coexistence of multiple phases (rhombohedral, tetragonal and orthorhombic) in BST, enhancing its properties (ε' = 6118 at RT, Pr = 5.50 μC/cm2, Q11 = 0.060 m4/C2, d*33 = 526 pm/V) in comparison to BTO. These results acknowledge the role of substituents in lattice disruption, paving the way for chemistry-based materials design in the field of dielectric, actuator and energy storage applications.

Improvement of ferroelectric properties via Zr doping in barium titanate nanoparticles

Barium titanate is still the prototype of a piezoelectric crystalline material that has attracted many researchers and industrial partners to use. A modified citrate method was used to create barium titanate nanoparticles BaTi1−xZrxO3. The samples were crystallized in a single-phase tetragonal structure, as revealed using X-ray powder diffraction. The crystallite size decreases with increasing Zr concentration. Fourier-transform infrared spectra showed the main absorption bands of the samples BaTi1−xZrxO3. Field emission scanning electron microscopy micrographs illustrate that the doped sample BaTi0.9Zr0.1O3 is more porous and finer than the parent. For low Zr doping concentrations (x = 0.1), the ferroelectric properties of barium titanate are improved. The conduction mechanisms in the samples are small polaron hopping and correlated barrier hopping. The Zr/Ti ratio is a crucial parameter for tailoring the ferroelectric–paraelectric phase transition.

The Effect of Calcination Temperature on the Structural Properties of BaTiO<sub>3</sub> and (Ba<sub>0.85</sub>Ca<sub>0.15</sub>)(Zr<sub>0.1</sub>Ti<sub>0.9</sub>)O<sub>3</sub> Using the SSR Method

This paper studies how the various calcination temperatures affect the structural properties of Barium Titanate (BaTiO3) and (Ba0.85Ca0.15)(Zr0.1Ti0.9) (BCZT) using solid-state reaction methods. BaTiO3 and BCZT powders are calcined at various temperatures ranging from 1100°C–1300°C. Using X-ray diffraction, the phase formation, crystal structure and crystallite size of BaTiO3 and BCZT powders were determined. The cubic crystal structure has been formed for BaTiO3 and BCZT. At 1200°C, the reaction between BaCO3 and TiO2 was complete to produce BaTiO3 composition. For BCZT composition were not fully react based on the phase structure in XRD due to impurity peak. Next, the crystallite size of BaTiO3 powder becomes larger with increasing calcination temperature. Meanwhile, BCZT crystallite size becomes smaller when the calcination temperature is increased has discussed at the end of this paper.

Effect of donor and acceptor dopants on the microstructure and dielectric properties of barium titanate based ceramics

This paper examined the microstructural and dielectric characteristics of BaTiO3 - based ceramics of the general formula BaTi1-x-yNbxMnyO3. The concentration of Mn as acceptor was variable 0.01 and 0.05 at%, while the donor (Nb) was fixed at 0.5 at%. The starting ceramic powders were produced by a conventional solid-state reaction method and sintered at 1290 and 1320oC. In BaTiO3 ceramics doped with a higher Mn concentration (0.05 at% Mn) at a sintering temperature of 1290?C, a bimodal structure with a grain of 10-30 ?m, and 1-5 ?m, was obtained. Sintering at a higher temperature (Tsin = 1320?C), regardless of Mn content, provides the achievement of a uniform microstructure with grains under than 6 ?m. The ceramics doped with 0.01 at% Mn and sintered at 1320?C are characterized by high values of the dielectric constant at room temperature and notable changes in the dielectric constant with temperature. Nb-0.05Mn BaTiO3 doped ceramics sintered at 1290?C show lower dielectric constant values due to the presence of Mn-enriched areas representing paraelectric regions. Areas richer in Mn are associated with the fine-grained structure. The dielectric constant in the investigated systems achieves a constant value for frequencies higher than 3kHz. The Curie temperature of all samples was shifted to lower values in relation to undoped BaTiO3 ceramics. According to Curie-Weiss law were determined the Curie constant C and the Curie temperature Tc.

Study on the addition of SiO2 nanowires to BaTiO3: Structure, morphology, electrical and dielectric properties

The effects of adding silicon dioxide (SiO2) nanowires on the properties of barium titanate (BaTiO3) were investigated. The structure, morphology and optical properties were examined using X-ray powder diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and ultraviolet–visible diffuse reflectance spectrophotometry (DR). All of the prepared samples crystallized with a cubic BaTiO3 structure. When the SiO2 content was <2.0 wt%, no secondary phase was observed and the (BaTiO3)1–x/(SiO2)x samples exhibited a microstructure with small grains. However, Ba2TiSi2O8 was detected upon further increasing the SiO2 content. When compared to the pure BaTiO3 sample, a slight increase in the Eg value was observed for the (BaTiO3)1–x/(SiO2)x composites. The dielectric and electrical measurements were used to analyze the dielectric constant (ε′), dissipation factor (tan(δ)), conductivity (σac) and impedance (Z). The results demonstrate that the addition of SiO2 nanowires affects the properties of BaTiO3. The study highlights the importance of SiO2 nanowires in BaTiO3 for use in microwave device applications.

Electrical and Mechanical Properties of Modified Barium Titanate by Doping an M-Type Hexagonal Ferrites

Effects of M-type barium hexaferrite (BH) on phase, microstructure, mechanical and electrical properties of barium titanate doped with Zr or MBT-xBH ceramics were systematically investigated. All ceramics presented pure perovskite structure with orthorhombic phase. Average grain size and porosity decreased while hardness increased with increasing BH and showed the highest value of 6.01 GPa for the 1.0 mol% sample. The mechanical properties improvement was related with the change in microstructure and porosity. The BH doping enhanced room dielectric constant by 266% with reduction of dielectric loss value (@1 kHz). Furthermore, grain size was found to affect with the change in strain behavior.

Factors affecting morphological and electrical properties of Barium Titanate: A brief review

Abstract Lead Zirconate Titanate has been extensively used to make ultrasound transducers, sensors, and actuators as well as high-value ceramic capacitors for a very long time. The main disadvantage of Lead Zirconate Titanate is its toxic nature due to the presence of Lead, which has been banned in most of the nations around the globe. In search of Lead-free materials as a suitable replacement to Lead Zirconate Titanate, Barium Titanate is a very strong candidate. It can be used as an electrical insulator in its purest form. Doped Barium Titanate is a promising tunable material with enhanced ferroelectric and piezoelectric properties which can be a good alternative to Lead Zirconate Titanate. Properties of Barium Titanate are found to change with preparation routes, doping, and other factors. Variation in dielectric constant and high permittivity makes Barium Titanate a useful material for many applications in modern electronic devices. In this paper, analysis has been done on the changes that occur in the properties of Barium Titanate with different factors like crystallographic orientation, grain size, texturing, doping concentration, and sintering process. The piezoelectric property makes Barium Titanate useful for many applications like semiconductors, positive temperature-coefficient resistors, transducers, and ceramics. From the perspective of future applications, materials possessing good fracture toughness improved piezoelectric and dielectric properties, and higher temperature stability is needed. Therefore, it is concluded that the properties of Barium Titanate are enhanced when doped with suitable materials like Mn, Ce, Ti, Fe, Zr, etc. and by adopting different preparation routes like the sol–gel method, hydrothermal method, chemical alloying method, co-precipitation method, and polymeric precursor method.

P.591 Orexin-A ameliorates lasting effects of postnatal dysfunctioning of muscarinic cholinergic system on sleep-wakefulness

Needle domains are thin, lamellar domains that can appear as fine lines or stripes in a ferroelectric crystal. They affect the poling, switching, and other properties of ferroelectrics. A model is established to study the stress and electric fields caused by needle domains and their interaction. Considering the electrical and mechanical compatibility conditions at the tip of a needle domain, the fields are represented using equivalent edge dislocations and line charges. Accordingly, the dislocation fields derived by Barnett and Lothe for anisotropic piezoelectric media are employed. A modified Peach–Koehler force and calculations of the total energy due to the needle domains are used to study the formation, interaction and stability of needle patterns, taking full account of the strong anisotropy and electromechanical coupling present.The interaction of pairs of needle domains in an infinite piezoelectric with properties of barium titanate is found to be dominated by the electrostatic terms. This makes comb-like arrays of needle domains unstable if perfectly insulating properties are assumed. By considering redistribution of charge, stable equilibrium states for arrays of needle domains are found; these agree well with experimental observations. The model explains the stability of various observed needle patterns and also how unstable patterns evolve.

Effect of Nickel and Cobalt co-substitution on the structural and dielectric properties of Barium Titanate ceramics

The influence of Nickel and Cobalt co-substitution on the structure and dielectric properties of barium titanate (BaTiO3) ceramics has been investigated. Nickel and Cobalt co-substituted BaTiO3 ceramics with general formula BaTi1−x(Ni,Co)xO3 has been synthesized for x = 0.0, 0.02, 0.04 and 0.08 through conventional solid state reaction route. The structural analysis carried out by X-ray diffraction reveals the successful incorporation of Ni2+ and Co2+ ions in the Ti4+ site of BaTiO3 with all samples under study having tetragonal structure. However the tetragonality (c/a ratio) seems to be decreasing with increase of co-substitution. The dielectric measurements are done at different frequencies and temperatures. The room temperature dielectric constant decreased considerably for the Ni and Co co-substituted samples. The phase transition of the BaTi1−x(Ni,Co)xO3 has been investigated by studying the temperature dependence of dielectric constant. Nickel and Cobalt co-substituted samples showed diffused nature of phase transition with a notable reduction in the Curie temperature with the increase of co-substitution. The Curie temperature is reduced to 104 °C for x = 0.08 composition whereas for x = 0.0 the Curie temperature is 123 °C. Enhancement in conductivity is observed with addition of Nickel and Cobalt addition. Nearest-neighbour hopping model is used to explain the conduction in the samples under study and energy of activation for conduction is calculated from Arrhenius plot.

Modelling and interaction of needle domains in barium titanate single crystals

Needle domains are thin, lamellar domains that can appear as fine lines or stripes in a ferroelectric crystal. They affect the poling, switching, and other properties of ferroelectrics. A model is established to study the stress and electric fields caused by needle domains and their interaction. Considering the electrical and mechanical compatibility conditions at the tip of a needle domain, the fields are represented using equivalent edge dislocations and line charges. Accordingly, the dislocation fields derived by Barnett and Lothe for anisotropic piezoelectric media are employed. A modified Peach–Koehler force and calculations of the total energy due to the needle domains are used to study the formation, interaction and stability of needle patterns, taking full account of the strong anisotropy and electromechanical coupling present.The interaction of pairs of needle domains in an infinite piezoelectric with properties of barium titanate is found to be dominated by the electrostatic terms. This makes comb-like arrays of needle domains unstable if perfectly insulating properties are assumed. By considering redistribution of charge, stable equilibrium states for arrays of needle domains are found; these agree well with experimental observations. The model explains the stability of various observed needle patterns and also how unstable patterns evolve.

Improved properties in Dy3+ substituted barium titanate

ABSTRACTIn this paper, effect of Dy3+ substitution on structural, microstructural, dielectric, ferroelectric and piezoelectric properties of barium titanate has been studied. Results of density measurement indicates that substitution of Dy3+ results in increase in density of BT. Grain size increases significantly with the substitution of Dy3+. Dy3+ substituted BT sample possess higher dielectric constant, better ferroelectric properties but weak piezoelectric properties.

Modification in properties of barium titanate on Sm3+ substitution

ABSTRACTEffect of substitution of Sm3+ on various properties of barium titanate has been studied. Barium titanate (BT) and its Sm3+ substituted derivative has been synthesized using solid state reaction method. X-ray diffraction analysis clearly indicated decrease in lattice constant of BT on Sm3+ substitution. Grain size increases significantly with the substitution of Sm3+. Sm3+ substituted BT sample possesses higher dielectric constant and better piezoelectric properties.

Effect of nickel and lithium co-substituted barium titanate ceramics on structural and dielectric properties

The effect of Ni and Li co-substitution on the structural and dielectric properties of barium titanate (BaTiO3) ceramics has been investigated. Ni and Li co-substituted barium titanate (BT) with general formula Ba(1−x)LixNix/2TiO3 where x = 0, 0.02, 0.04, and 0.08 is synthesized using microwave-assisted heating. This synthesis process extraordinarily reduced the processing time to 1 h, which includes heating and the dwell durations. The XRD investigation confirmed the formation of a single phase tetragonal structure with a space group of P4mm. The surface morphology of the sintered samples exhibits a high density and a homogeneous distribution of the grains. Impedance analyzer was used to measure the dielectric constant and loss tangent values at different frequencies as well as at various temperatures range. Ni and Li co-substituted BaTiO3 shows many interesting features, such as shifting of phase transition towards higher temperature, increasing in dielectric constant, decreasing in dielectric loss and increasing in diffuse phase transition with increased frequency. The activation energy of all samples was investigated using Arrhenius plots.

Preparation and properties of Barium titanate (BaTiO3) reinforced high density polyethylene (HDPE) composites for electronic application

In this study, 3-Aminopropyltriethoxysilane (KH550) with polar amino groups is applied to modify the surface of Barium titanate (BaTiO3) particles. When volume fraction of BaTiO3 further increases to 50 vol%, the dielectric constant and loss of HDPE control increase from 2.5 and 0.02 to 18.5 and 0.10 at 10 MHz, respectively, with the volume resistivity of HDPE control decreasing from 3.6 × 1013 Ω m to 3.5 × 1011 Ω m. The increased amount of modified BaTiO3 can increase the flexural strength and modulus HDPE composites from 8 and 90 MPa to 14 and 780 MPa, respectively. However, the increase of modified BaTiO3 can restrict mobility of HDPE chains and decrease the crystallinity of HDPE composites.

Properties and Phase Shift Structure of (1-x)BT-(x)BNT Ceramics

In the research, the properties of barium titanate - bismuth sodium titanate [(1-x)BaTiO3-(x)Bi0.5Na0.5TiO3: (1-x)BT-(x)BNT] ceramics prepared by conventional mixed oxide method with various molecular weight of BNT or x between 0.0 and 0.3 were investigated. The optimum condition for calcined powders of x = 0.0 was found at 900 °C for 2 h, and x = 0.1 - 0.3 were found at 850 °C for 2h. The calcined powders were pressed and sintered at 1000 – 1200 °C for 2h. The phase structure was examined by x-ray diffraction (XRD). The microstructure was examined by scanning electron microscopy (SEM). Density of sintered samples was measured by Archimedes method with distilled water as the fluid medium. It was found that, all various x of (1-x)BT-(x)BNT ceramics XRD patterns display the tetragonality increased with increasing sintering temperature. All the peaks shift to higher angles when increasing x value indicating the decrease of lattice parameter “a” and increase of lattice parameter “c”. The average grains size of (1-x)BT-(x)BNT ceramics was increased with increasing sintering temperature. The highest density was 5.53 g/cm3 and was obtained from the sample sintered at 1200 °C.

Effect of Substitution of Samarium and Lanthanum on Dielectric and Electrical Properties of Barium Titanate

In this research paper, we report the dielectric and electric investigation of series of dielectric ceramics samples with structural formula Ba2-xRe4+2x/3Ti8O24 (where Re = Sm and La and x = 0.0, 0.2, 0.4 and 0.6). The dielectric parameters (i.e. dielectric constant and loss tangent) and ac conductivity are measured with impedance analyzer. This paper is presented to compare the effect of samarium and lanthanum doping on the properties of barium titanate. The research work concludes that lanthanum doping has more favorable effect on the properties. This paper also presents impedance analysis and V-I characteristics of all the samples. This is concluded that these properties are strongly dependent on frequency, temperature and composition. The investigation reports almost constant value of dielectric constant and very low loss tangent at lower temperatures.

Composition-Microstructure-Property Relationships in BaTiO&lt;sub&gt;3&lt;/sub&gt; with Mg Addition

Rising worldwide demands for energy encourages development of high-efficiency energy storage and capacitor components. Main requirements for dielectric materials employed in fabrication of high energy density capacitors include high dielectric constant, high dielectric breakdown strength, and low dielectric loss. Owing to its high dielectric constant and low dielectric loss [1], barium titanate is among common capacitor materials. Tailoring of dielectric properties of barium titanate can be achieved through controlled chemical composition, microstructure, and crystal structure. Synthesis and processing techniques, as well as doping of barium titanate, can be key factors to control the composition and structure, which consequently contribute to enhancement of dielectric constant in the material.

Material constants of barium titanate thin films

The nonlinear properties of barium titanate lead to changes in the material constants of the linear equations for the piezoelectric effect in thin films. The behavior of the material constants of single-crystal barium titanate thin films at room temperature has been studied as a function of the misfit strain in terms of the Landau potential of the phenomenological theory. Most of material constants exhibit anomalies at the interfaces with variations in the strain. In the r phase, some elastic and electroelastic constants reach an extremum. The obtained results indicate lines of the search for obtaining films with necessary properties.

Structural Studies of BaTiO&lt;sub&gt;3&lt;/sub&gt; Ferroelectric Material Prepared by Green Chemistry (Sol-gel) Method

Nano particle Barium Titanate (BT) is the first ferroelectric ceramics and a good nominee for a variety of applications from large family of Perovskite. In this study BaTiO 3 was synthesised by using Sol-gel (green chemistry) method. It is environmental friendly method and has a significant influence on the structure and properties of BT. XRD patterns were indexed on the basis of tetragonal-BaTiO 3 phase. The microstructure of the samples was investigated by using Scanning electron microscope (SEM). The grain size range was 90 nm for the dried gel powder for the powder calcined at . 1150°C. Infrared (IR) spectrum was recorded at room temperature. The absorption peak observed at 545 cm -1 found to be BT characterization peak.

Enhanced dielectric performance of BaTiO3/PVDF composites prepared by modified process for energy storage applications.

Ceramic-polymer composites have attracted extensive attention in electrical applications due to their high permittivity and low loss. In this work, we report the studies on the preparation and properties of barium titanate (BT)/ poly(vinylidenefluoride) (PVDF) composite thin films. The composite film was prepared by a modified process rather than the conventional method. The modified process adopted ballmilling technique instead of the stirring method to disperse BT nanoparticles into PVDF solution. Scanning electron microscopy images of the obtained composites show that the BT nanoparticles are incorporated into the PVDF network and are well dispersed in the matrix. When the BT volume fraction is 30%, the permittivity and breakdown strength of the composites reach their optimal values and the energy density reaches maximum value (5.3 J/cm3), an increase of 80% compared with that of the composites prepared using the stirring method. Another modification is the use of acetone and butanone mixed solution instead of N,N-dimethylformamide to dissolve the PVDF, which is beneficial to form pure α-PVDF composite films on the polyethylene terephthalate substrate by tape casting. The composites prepared by the modified process, with high permittivity and significantly enhanced breakdown strength, are useful candidates for energy storage applications.