Space Group Pm3m Research Articles

From NdNiO2 to a Mott Multiferroic BiNiO2

Motivated by the recently discovered superconductivity in Sr-doped nickelate oxides NdNiO2 reduced from NdNiO3 in experiments, we predict a Mott multiferroic BiNiO2 that may be obtained from BiNiO3. There is a ferroelectric structural transition for BiNiO2 from the nonpolar phase to the polar phase with the P4mm space group, which is driven by the lone pair on Bi. The lowest energy ground-state for polar BiNiO2 is a Hubbard Mott insulator with the G-type antiferromagnetic spin configurations. The replacement of Nd by Bi serves as a connecting link between a parent compound of high-temperature superconductor and a Mott multiferroic.

Investigations of the magneto-dielectric and multiferroic properties in of Bi0.90Dy0.10FeO3-BaTi0.95Hf0.05O3 composite

Sol-gel method is used to synthesize the Bi0.90Dy0.10FeO3-BaTi0.95Hf0.05O3 (BDyFO-BTHfO composite) multiferroic composite material. The structural formation was examined utilizing an X-ray diffraction (XRD) pattern preceded by Rietveld refinement utilizing the FULLPROF programme to confirm the presence of tetragonal and partially rhombohedral structures having space group P4mm and R3c, respectively. The dielectric characteristics of the BDyFO-BTHfO composite have been measured with respect to frequency (100 Hz to 1 MHz) and temperature (RT to 663K). Dielectric permittivity (ε) shows low-frequency dispersion which can be addressed by Maxwell-Wanger-type interfacial polarization. The synthesized composite material exhibits a negative magneto-dielectric (MD) effect when a magnetic field is operated (0.0 T to 2.0 T) and the obtained values are −9.61% and −19.68% for the ε and tanδ, respectively, at 1 kHz. The contribution of the grains, grain boundaries and electrode effects on the resistive characteristics of the samples was evaluated using comprehensive impedance spectroscopy using a Nyquist plot. The band gap (Eg ) absorption of the synthesized sample was determined using Tauc’s formula and found to be 2.05 eV. The BDyFO-BTHfO composite has improved magneto-dielectric, magneto impedance, and optical properties that support their potential usage in microelectronics, energy storage devices, and optoelectronic devices.

Structural Evolution, Dielectric, Ferroelectric and Thermal Properties of Pristine and (Sr, Mn) Co-doped BaTiO3

Nanocrystalline specimen of pure BaTiO3 (BTO) and Ba0.9Sr0.1Ti0.95Mn0.05O3 (BSTMO5) has been synthesized through solid state route. XRD patterns reveal uni-phase tetragonal configuration with P4mm space group. The crystallite size and strain have been evaluated by fitting the data with Williamson-Hall equation. Raman spectra are consistent with the tetragonal phase of BTO. Colossal value of dielectric constant is observed for BTO samples. The temperature-dependent P-E loops reveal highest value of polarization at 323K. Differential thermal analysis (DTA) is used to evaluate the specific heat (Cp) of the samples. Doping with (Sr, Mn) raises the Curie temperature hence enhancing the temperature stability of BTO. It can broaden the temperature range over which the material exhibits desirable ferroelectric and dielectric properties. This improved stability along with high dielectric permittivity is advantageous for applications that require operation over a wide temperature range. The band gap enhanced for BSTMO5 making it suitable for usage in optoelectronic devices.

Structural, electronic, mechanical, and optical properties of the lead-free halide perovskites XGeCl3(X = Cs, K, and Rb) for the photovoltaic and optoelectronic applications

The present investigations into the chloroperovskites CsGeCl3, KGeCl3, and RbGeCl3 are conducted by using the density functional theory-based CASTEP tool with the GGA-PBE method. The space group Pm-3m (221) is used. The computed values of lattice parameters are CsGeCl3: 5.34 Å, KGeCl3: 5.26 Å, and RbGeCl3: 5.29 Å, and also an inverse relationship between volume and density is observed. Total density of states (DOS) and partial density of states (PDOS) calculations are performed to assess the semiconducting properties of the materials. The calculated energy bandgaps, indicative of their direct semiconducting nature are as follows: CsGeCl3: 1.076 eV, KGeCl3: 0.874 eV, and RbGeCl3: 0.952 eV. In the context of mechanical properties, the various mechanical parameters are determined using single-elastic constants, revealing that XGeCl3 (X=Cs, K, Rb) exhibits mechanical stability and anisotropic characteristics. Furthermore, all materials are ductile and hard because Pugh's ratio is greater than 1.75 and Vicker's hardness is less than 40 GPa, respectively. All materials contain the same value of compressibility. Regarding optical characteristics, the loss function, refractive index, dielectric function, optical conductivity, absorption, and reflectivity are comprehensively studied. It is found that the strong peaks of absorption, conductivity (Re & Im), plasmon peak, dielectric functions (Im), refractive indices (Im), and reflectivity fall in the UV region (10 nm-400 nm), while the largest peaks of dielectric functions (Re) and refractive indices (Re) parts belong to the visible region (400 nm- 700 nm). These compounds hold significant promise for applications in photovoltaics and optoelectronics.

Enhancement of dielectric and ferroelectric properties of (Sr, Ni) Co-doped BaTiO3 ceramics

In the present study, systematic investigations on dielectric and ferroelectric properties of pure and (Sr, Ni) co-doped BaTiO3 nanocrystalline powder samples fabricated via microwave-assisted co-precipitation method have been reported. XRD patterns divulge the formation of mono-phase tetragonal crystal structure with P4mm space group. The fingerprint bands in the FTIR spectra further assure the formation of desired crystal structure. The dielectric responses have been examined by virtue of the universal dielectric response mechanism with remarkable improvement in the dielectric properties for the (Sr, Ni) co-doped sample. The P-E loop measurement corroborates ferroelectricity in the system and augmentation in the maximum polarization for the co-doped sample. The improved dielectric and ferroelectric properties in (Sr, Ni) co-doped BaTiO3 suggest its potential in various technological applications.

Structural, dielectric and electrical properties of (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 ferroelectric ceramic

In this report, the proposed compound (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 is synthesized by mixed oxide route for the extensive study of the dielectric and electrical properties. The crystallization, symmetry, structure (tetragonal), space group (P4mm), and lattice parameters were confirmed by an X-ray diffraction study. The dielectric and electrical properties in a wide range of temperatures and frequencies of this particular composition deduce various interesting properties on high dielectric permittivity, low tangent loss, relaxation mechanism, non-Debye type conduction, and negative temperature coefficient of resistance. From the frequency and temperature dependence, dielectric loss shows a very low loss factor (<0.06) at low temperatures (<250 °C). Nyquist plots discuss the contribution of grain and grain boundary by fitting it with the help of the software ZSimpWin. The PE loop measurement showed that the corresponding hysteresis had main parameters for (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 compound, remnant polarization (Pr = 0.28 µC/cm2) and coercive field (Ec = 1.35 kV/cm). All the above characteristics conclude that it may be applicable in electronic device industries.

Structural and dielectric properties of Y3+ doped SrTiO3: a novel anode materials for solid oxide fuel cell

An ongoing and elusive task is to create single phase anode materials for solid oxide fuel cells (SOFC). Compared to the typical Ni-YSZ cermet anode, perovskite oxide based anode material has a number of benefits. Here, we present the structural and electrical characteristics of Y3+ doped SrTiO3 ceramics that are used as the anode in solid oxide fuel cells. The samples with nominal composition x = 0 and 0.05 were synthesized by high energy ball milling. The powder X-ray diffraction pattern reveals that the synthesized samples crystallize into cubic crystal structure with space group Pm3m for both the compositions. The samples were sintered at a temperature of 1300 °C for 6h. The sintered density of the samples was found to be greater than 97%. The temperature dependent dielectric measurement studies reveal that dielectric constant increases with yttrium doping and shows relaxer behavior. A higher dielectric constant and electrical conductivity was observed for the Y-doped sample which fulfill the basic requirement for anode materials of solid oxide fuel cells.

Insights into structural, electronic, optical properties, and impedance spectroscopy of semi-doped perovskite Nd0.5Ba0.5CoO3: A theoretical and experimental study

In this study, the electronic, structural, and optical properties of semi-doped perovskite Nd0.5Ba0.5CoO3 (NBCO) were investigate using the CASTEP software, which relies on density functional theory (DFT) along with the correlation function of generalized gradient approximation (GGA) and Perdew-Burke-Ernzerhof (PBE). The mesh parameters of the (super) cell indicate that NBCO adopts an orthorhombic structure in the Pmmm space group, featuring a Coulomb Energy (EC) of approximately −244 eV. DFT and total density of states (DOS) analyses reveal that the as-prepared perovskite manifests metallic characteristics, and a notable covalent interaction is observed between the O-p and Co-d spin states, indicating strong hybridization between these orbitals. Remarkably, NBCO demonstrates 100 % spin polarization (P) at the Fermi level, with a calculated total magnetic moment of approximately 3.44 μB. Moreover, low dielectric loss (tgδ) values suggest facile electron movement, and impedance spectroscopy illustrates a dielectric relaxation phenomenon. DFT calculations predict an orthorhombic crystal structure with higher electron density at cobalt atom positions. Band structure and DOS analyses affirm metallic behavior owing to the robust hybridization between oxygen-p and cobalt-d orbitals. Optical property assessments reveal potential applications in spintronics and optoelectronics, with notable absorption in the ultraviolet–visible range. The conductivity spectra from impedance spectroscopy contribute to understanding temperature-dependent charge transport mechanisms. Dielectric constants decrease with increasing frequency and temperature, while dielectric losses remain low, indicating efficient electron movement. The material adheres to a metallic conduction mechanism as described by Drude's law, and the material's 100 % spin polarization at the Fermi level and a total magnetic moment of 3.44 μB are significant findings. Negative dielectric constants observed at specific frequencies suggest potential applications in metamaterials. Overall, the determined properties position NBCO cobaltite as a promising candidate for high-frequency devices, spintronic components, and sensors.

Effect of A-site cobalt doping on the structural, micro-structural and dielectric properties of (Ba1-xCox)(Ti0.95Zr0.05)O3 lead-free ceramics

Cobalt-doped barium zirconate titanate ceramics with (Ba1-xCox)(Ti0.95Zr0.05)O3 with (x = 0, 2.5, 5, 7.5 and 10 %) were synthesized by sol-gel process. The effects of Ba/Co ratio on structural, micro-structure properties and dielectric response were investigated by varying the value of x. X-ray diffraction analysis and the Rietveld refinement method revealed that the ceramics have a single phase with a tetragonal structure of the P4mm space group. The scanning electron microscope (SEM) was used to examine the texture, morphology and microstructure of the (Ba1-xCox)(Ti0.95Zr0.05)O3 ceramics. The analysis showed a decrease in average grain size as the concentration of Co2+ ions in the crystal structure increased. A study of the impedance spectroscopy of the dielectric measurements was carried out in a temperature range from room temperature to 200 °C, and revealed that the ferroelectric to paraelectric phase transition temperature decreases proportionally with increasing cobalt concentration, confirming the incorporation of Co2+ and highlighting its influence on the Curie temperature (Tc), the value of the permittivity (εr) and dielectric losses (tanδ). The Curie-Weiss law was used to study the nature of the transition, revealing that diffusivity increases in correlation with the Co2+ ion concentration.

First principle investigation of tungsten based cubic oxide perovskite materials for superconducting applications: A DFT study

Perovskite will play an important role in the materials study to investigate the different properties. The CASTEP (Cambridge Serial Total Energy Package) code will be used to investigate the material properties. The structural, electronic, thermodynamic, and optical characteristics of novel tungsten-based oxide-perovskite materials WXO3 (where X = Cr and Hg) were investigated by using first principle calculations (CASTEP) with ultra-soft pseudo-potential PW (plane wave) and GGA (generalized gradient approaches)-PBE (Perdew-Burke-Ernzerhof) exchange correlation-functional. According to the calculations, both compounds have a space group of PM3m with a cubic structure. The results we discovered are entirely novel compounds, as demonstrated by computations. According to calculations, the band structure of WXO3 has a zero band gap. The graphical interpretations like DOS (density-of-states), partial DOS, and band structure in both perovskite materials reveal conclusive proof of conductive behavior. The presence of ionic bonds is revealed by a study of bonding characteristics shown by Poisson's ratios of 0.71 and 0.49 for WCrO3 and WHgO3, respectively. The WCrO3 and WHgO3 optical characteristics have also been studied and assessed. The Fermi level will be so highly overlapped that most of the electrons will lie from the conducting valence band VB to the conduction band CB and vice versa. Thermodynamic characteristics are studied, like Debye temperature, sound velocity, melting temperature, and compressibility. These compounds are extensively used in medical devices, sensitive devices, computer parts, and storage systems. Further investigation will be required on these materials with doping any element to enhance the band gap to study the other properties like photocatalytic and solar cell applications.

Optical, Dielectric, and Electrical Properties of Tungsten-Based Materials with the Formula Li(2−x)NaxWO4 (x = 0, 0.5, and 1.5)

In the present study, three chemical compounds, Li2WO4, Li0.5Na1.5WO4, and Li1.5Na0.5WO4, are produced using the solid–solid method. Unlike the compound Li0.5Na1.5WO4, which crystallizes in the orthorhombic system with the space group Pmmm, both compounds Li2WO4 and Li1.5Na0.5WO4 crystallize in the monoclinic system with the space group P2/m. A morphological analysis reveals that all three compounds have a compact structure with some porosity present. An EDX analysis confirms the chemical composition of the three samples. The optical measurements provide information on the optical gaps and Urbach energies of the materials under consideration. Their dielectric characteristics are investigated in a frequency range of 100–106 Hz and at temperatures ranging from 300 to 600 K. Moreover, this research enables us to determine the ferroelectric transition as well as the type of dielectric material. In this study, an investigation of electrical conductivity was conducted for well-defined temperature and frequency values; which provided us with information about the mechanism of conduction and charge carrier transport models.

Study on the composite structure of cobalt-free oxides as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs)

Summary: Solid Oxide Fuel Cells (SOFCs) represent a promising technology for efficient and clean energy conversion. This study focuses on the design and development of a novel cathode material for SOFCs, specifically exploring the use of a free-cobalt cathode within a composite structure. Investigating the structure of cobalt-free composites of Ba0.5Sr0.5FeO3-δ (BSF) and Ba0.5Sr0.5Fe0.8B0.2O3-δ (B=Cu, Zn) (BSFB) have been prepared and evaluated as cathodes for IT-SOFCs. The solid-state reaction was employed for generating and modifying the composite structure of the model system. The decomposition reaction and the formation of perovskite structure have been observed using thermal gravimetric analysis and X-ray diffraction. The study encompasses experimental procedures, data processing using GSAS software, and the application of the Rietveld method to achieve precise analysis results. Rietveld analysis outcomes offer intricate details about the crystal structure, encompassing crystal unit parameters, and scale factors. The solid-state reaction led to the reduction in the weight of the composite during the heating process. The decomposition reaction of oxides was generated between 650 to 950 oC. The average of total weight loss during the period treatment was achieved up to 18 % and the perovskite phase formed in the composite structure. A single-phase perovskite from a cubic structure with space group Pm-3m was demonstrated by all composite’s models. The lattice parameter and a unit cell volume were obtained from the model system of BSF, BSFC and BSFZ, respectively. This study explores the potential development of SOFCs technology with the hope of making a positive contribution to advancing clean and sustainable energy solutions in the future

Structure and microwave dielectric properties of Al3+-doped (Zn1/6Ba1/6Ca1/6Sr1/6La1/3)TiO3 high-entropy ceramics system

In this study, based on the highly disordered multi-component system with high-entropy and traditional perovskite with high dielectric constant, a series of the Al3+-doped high-entropy perovskite (Zn1/6Ba1/6Ca1/6Sr1/6La1/3)Ti1-xAlxO3 (0 ≤ x ≤ 0.1) ceramics was designed and synthesized by using a solid state reaction method to explore the effects of different doping amounts on microwave dielectric characteristics together with the microstructures. The single-phase structure in space group Pm-3m was determined in the sintering temperature range of 1325 °C–1400 °C and both had high dielectric constant (from 74.46 to 93.44). With the increase of Al doping amount, the variation trend of dielectric constant was closely related to the density and ionic polarizability. The Q × f value of doped samples was higher than that of undoped samples, which was mainly due to the interaction of oxygen vacancy content and grain size. Due to the high-entropy effect resulting in [Ti-O6] octahedral torsion, the τf value was greatly reduced compared with traditional perovskite, which exhibited outstanding microwave dielectric properties (εr = 74.46, Q × f = 4108 GHz at 4.31 GHz, and τf = +184 ppm/°C). The present work provided an effective approach to improve the properties of microwave dielectric ceramics.

Structural, morphological, optical and biomedical applications of Berberis aristata mediated ZnO and Ag-ZnO nanoparticles

Herein, we prepared the zinc oxide (ZnO) and silver doped zinc oxide (Ag-ZnO) nanoparticles (NPs) using Berberis aristata plant extract as a reducing, capping and stabilizing agent. The x-ray diffraction (XRD) pattern confirms the formation of pure hexagonal wurtzite structure for both the samples with P4mm space group. The crystallite size reduces from 21.313 nm to 18.179 nm with the Scherrer technique with doping of Ag ions on ZnO NPs, while the Williamson Hall (WH) approach likewise demonstrates a decrease in crystallite size from 26.602 nm to 21.522 nm. The lattice strain increases from 0.0031 to 0.0064, indicating the presence of Ag-ions in the crystal lattice of ZnO NPs. For both samples, the metal-oxygen bond formation is supported by the Fourier Transform Infrared (FTIR) spectra. For ZnO, the peak in the UV-visible spectrum is approximately around 365 nm, but for Ag-ZnO, two peaks are observed around 235 nm and 360 nm. With the Ag doping, the bandgap increases from 3.01 eV to 3.02 eV. Transmission Electron Microscopy (TEM) micrographs show the formation of crystalline particles and Field Emission Scanning Electron Microscopy (FESEM) pictures show the formation of aggregated NPs with a spherical shape. Energy Dispersive x-ray Spectroscopy (EDX) and x-ray Photoelectron Spectroscopy (XPS) demonstrate the chemical purity of both the samples. The antibacterial activity of ZnO NPs was highest against Staphylococcus aureus i.e., 15 ± 0.53 mm, whereas, for Ag-ZnO NPs the highest activity was against Salmonella typhi i.e., 19 ± 0.53 mm.

Engineering room temperature multiferroicity and temperature dependent dielectric properties of Cr doped BaTiO3 ceramics

The coexistence of ferroelectricity, ferromagnetism, and piezoelectricity at room temperature in BaTi1-xCrxO3 (0 ≤ x ≤ 0.06) nanostructures is interesting and leads to the multiferroic nature of system. Sol-gel auto-combustion technique has been used for the synthesis of nanostructures. The XRD patterns along with Rietveld refinement analysis, confirm that the samples possess parent tetragonal perovskite structure in the P4mm space group. The oxygen vacancies stoichiometry ratio was estimated through XPS studies. The scanning electron microscopy (SEM) confirms the large grain size in the doped sample. The study of leakage current density reveals an increase in its value with the increase in Cr content due to defects induced in the system. P-E measurements confirm the ferroelectric nature of the samples that diminishes in the doped samples due to the high leakage current. Moreover, the estimated value of energy efficiency (η) was found to be maximum for the undoped sample. The undoped BaTiO3 has a diamagnetic character that is partially altered into weak ferromagnetic under the Cr-doping at the expense of decreasing polarization parameters. The temperature-dependent dielectric constant shows all characteristics of phase transitions in the samples. The doping of Cr enhances the ferroelectric to paraelectric phase transition temperature (Tc). The piezoelectricity remains preserved in the doped samples. Thus, the coexistence of ferroelectricity, ferromagnetism, and piezoelectricity at room temperature finalizes the multiferroic nature of the synthesized samples.

BZT substitution effect on the characteristics of (1-x) MT – x BZT composite ceramics synthesized by the sol–gel method

This paper addresses a crucial gap in the effect of adding BaZr0.1Ti0.9O3 (BZT) on the structural, microstructural, dielectric, and electrical properties of MgTiO3 (MT) material. These ceramics with the chemical composition (1-x) MT – x BZT were synthesized with different compositions ranging from × = 0.0 to 1.0 with a 0.1 step using the sol–gel reaction process. The X-ray diffraction (XRD) results and Rietveld refinement analysis showed the formation of a tetragonal phase with the P4mm space group for the BZT sample and a hexagonal phase with the R-3 space group for MT ceramics, without any secondary phases. However, (1-x) MT – x BZT composites with × ranging from × = 0.1 to 0.9, showed a coexistence of tetragonal (P4mm) and hexagonal (R-3) phases. Scanning Electron Microscopy (SEM) was used to investigate the morphology and grain size of the compounds. The SEM results revealed a clear decrease in grain growth for x = 0.6 of BZT content with the higher density. Furthermore, the dielectric properties of these composites were studied by impedance spectroscopy, which showed a single diffuse dielectric phase transition for all the BZT-MT composites. There was a clear increase in dielectric permittivity (εr′) value with the increase of the BZT content. This broad phase transition is highly desired and has not been observed in previous studies. The obtained composite ceramics could open the way to lead new applications in microelectronic devices.

Electrophysical Properties of PZT-Type Ceramics Obtained by Two Sintering Methods

This study demonstrates the impact of two sintering techniques on the fundamental properties of doped PZT-type ceramic materials (with Mn4+, Sb3+, Gd3+, and W6+), with the general chemical formula Pb(Zr0.49Ti0.51)0.94Mn0.021Sb0.016Gd0.012W0.012O3. The synthesis of ceramic powders was carried out through the calcination method. Two different methods were used in the final sintering process: (i) pressureless sintering (PS) and (ii) hot pressing (HP). The PZT-type ceramics were subjected to electrophysical measurements, encompassing various analyses such as X-ray diffraction (XRD), microstructure (scanning electron microscopy (SEM)), ferroelectric and dielectric properties, and DC electrical conductivity. The analysis of the crystal structure at room temperature showed that the material belongs to the perovskite structure from the tetragonal phase (P4mm space group) without foreign phases. Both sintering methods ensure obtaining the material with appropriate dielectric and ferroelectric parameters, and the tests carried out verified that the ceramic materials have a diverse range of parameters appropriate for use in micromechatronic and microelectronic applications. The obtained ceramic material has high permittivity values, low dielectric loss tangent values, and high resistance. At room temperature, the ceramic samples’ P-E hysteresis loops do not saturate at a field of 3.5 kV/mm (Pm maximum polarization is in the range from 12.24 to 13.47 μC/cm2). However, at higher temperatures, the P-E hysteresis loops become highly saturated, and, at 110 °C, the Pm maximum polarization values are in the range from 28.02 to 30.83 μC/cm2.

Effective calcium co-doping in Sm0.8Ca0.2Ba1-xCaxCo2O5+δ cathode materials for intermediate-temperature solid oxide fuel cells

High performance and durability of electrode materials are key requirements for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Herein, a novel doubles perovskite oxides Sm0.8Ca0.2Ba1-xCaxCo2O5+δ (x=0.1 and 0.2; SCBCC) were prepared by A site calcium co-doping strategy. x=0.1 sample shows stabilized an orthorhombic structure with the space group Pmmm. Compared with parent SmBaCo2O5+δ, substitution of Ca for Sm and Ba effectively reduces the thermal expansion coefficient (TEC) (20.2 × 10−6 K−1 to 13.2 × 10−6 K−1). x=0.1 sample exhibits excellent chemical compatibility with CeO2-based electrolytes up to 1000 °C, the conductivity values reach 340–400 S cm−1 at 600–800 °C. The sample with x = 0.1 showed the best catalytic activity and carbon dioxide resistance. The area specific resistance and maximum power density of the x= 0.1 cathode are 0.022 Ω cm2 and 885 mW cm−2 at 800 °C. x = 0.1 double perovskite has good chemical compatibility and electrochemical properties while greatly reducing TEC, making this double perovskite a promising material for IT-SOFCs.

Using (Ba,Ca)ScO2F:Bi3+,K+ phosphor with great performance and strong heating stability for LED backlight screens

diodes emit illumination (LED) display study is focused on straitband green phosphor samples yielding significant effectiveness as well as heating consistency. The cation substitution design technique was used to create Ba1-xCaxScO2F:0.001Bi3+,0.001K+ with x of 0-0.12) perovskite phosphors that emit strait green illumination when activated by a 415 nm chip. The impact of Ca2+ replacement for Ba2+ in the crystal structures of Ba1- xCaxScO2F:0.001- Bi3+,0.001K+ and photoluminescence characteristics were examined. In the space group Pm3m, all of the phosphors have a cubic perovskite-type structure. The development of cell characteristics and the lengthiness of the Ba/ Ca/K/Bi-O bonds were studied. Beneath 415 nm chip stimulation, the phosphors with an interior quantum effectiveness of 77.4 percent produce strong green radiation reaching the peak at 510 nm. The increase of luminous effectiveness and heating steadiness in response to local structural change was thoroughly addressed. The cation substitution design technique discussed here might be a significant way to realizing spectrum modulation by regulating the micro-surrounding within the latticework to achieve outstanding LED backlighting screens.

Investigation of Structural and Dielectric Properties of Sr doped LaCrO3Synthesized by Auto-Combustion Method

We synthesized the undoped lanthanum chromium oxide, LaCrO3 (LCO), and Strontium (Sr) doped La1-xSrxCrO3 (x=0.1) perovskite compounds using auto-combution method. X-ray Diffraction technique reveals that both the samples possess Cubic crystal structure with Pm-3m space group. Furthermore, room temperature dielectrical properties of both the samples were emphasized. Dielectric constant and loss value of both the samples decreases as frequency increases attributed to Maxwell-Wagner type of relaxation.