Synthesis,characterization and charge transport properties of Pr–Ni Co-doped SrFe2O4 spinel for high frequency devices applications

Ferrites are materials of interest due to their broad applications in high technological devices and a lot of research has been focused to synthesize new ferrites. In this regard, an effort has been devoted to synthesize spinel Pr–Ni co-substituted strontium ferrites with a nominal formula of Sr_1-xPr_xFe_2-yNi_yO₄ (0.0 ≤ x ≤ 0.1, 0.0 ≤ y ≤ 1.0). The cubic structure of pure and Pr–Ni co-substituted strontium ferrite samples calcinated at 1073 K for 3 h has been confirmed through X-ray diffraction (XRD). Average sizes of crystallites (18–25 nm) have been estimated from XRD analysis and nanometer particle sizes of synthesized ferrites have been further verified by scanning electron microscopy (SEM). SEM results have also shown that particles are mostly agglomerated and all the samples possess porosity. It has been observed that at 298 K, the values of resistivity (ρ) increase, while that of AC conductivity, dielectric loss, and dielectric constants decrease with increasing amounts of Pr³⁺ and Ni²⁺ ions. The values of dielectric parameters initially decrease with frequency and later become constant and can be explained on the basis of dielectric polarization. Electrochemical impedance spectroscopy (EIS) studies show that the charge transport phenomenon in ferrite materials is mainly controlled via grain boundaries. Overall, synthesized ferrite materials own enhanced resistivity values in the range of 1.38 × 10⁹–1.94 × 10⁹ Ω cm and minimum dielectric losses, which makes them suitable candidates for high frequency devices applications.     

Low‐Temperature Relaxations Associated with Mixed‐Valent Structure in Sr2TiMnO6

The dielectric properties of Sr₂TiMnO₆ ceramic samples were investigated as functions of temperature (100 K ≤ T ≤ 320 K) and frequency (100 Hz ≤ f ≤ 10 MHz). Two thermally activated dielectric relaxations were observed. The sample was confirmed to possess multivalent states of Mn and Ti ions and the coexistence of electron holes and electrons. Our results revealed that both relaxations are bulk effect related to localized carriers hopping inside grains. It was suggested that the low‐temperature relaxation (LTR) can be related to dipolar effect due to electron holes, and the high‐temperature relaxation (HTR) was associated with the electrons hopping between Ti³⁺ and Ti⁴⁺ ions.     

Solvothermal Synthesis of In2−xCoxO3 (0.05 ≤ x ≤ 0.15) Dilute Magnetic Semiconductors: Optical,Magnetic, and Dielectric Properties

Highly crystalline and monophasic nanoparticles of In_2?xCo_xO₃ (0.05 ≤ x ≤ 0.15) were successfully synthesized by the solvothermal method through an oxalate precursor route. Collective evidence from X‐ray diffraction and reflectance measurements suggest that the Co²⁺ is incorporated into the In₂O₃ lattice site. Effect of cobalt dopant on the growth and morphology of indium oxide was studied by transmission electron microscopy. It has been observed that particle size decreases from 23 to 9 nm on increasing the Co concentration. High surface area has been obtained, with values ranging between 66 and 151 m²/g, respectively. Values for the dielectric constant were around 40. All these solid solutions show paramagnetic behavior with weak antiferromagnetic interactions.     

Influence of B-site cations ordering on magnetization and dielectric relaxations in Li–Ni spinel ferrites

Ho-substituted Li–Ni ferrites with composition L i_1.2Ni_0.4Ho_xFe_2-xO₄; 0≤ x ≤ 0.15 were synthesized by a self-ignited sol-gel process. An annealing temperature of 950 °C is estimated via thermal-gravimetric (TGA) analysis. X-ray diffraction (XRD) scans have confirmed the formation of the ferrite phase with a spinel structure in all samples. Substitution of Ho ions on the B-site significantly reduced the porosity from 38 -to 23% and the crystallite size from 23.4 -to 21.7 nm. Microstructural analysis revealed a denser structure with an increase in Ho content. Dielectric results showed that both the dielectric loss and dielectric constant depict a nonlinear variation with the addition of Ho. Complex impedance behavior with a single semicircle for all samples suggests the predominant effect of the grain boundary mechanism. The substitution of Ho ions in place of Fe ions significantly decreased the electrical conductivity. The anisotropic Ho³⁺ ions reinforce the L-S coupling which consequently enhanced the coercive force from 145 -to 389 Oe, and thus the anisotropy constant.     

Low‐Temperature Magnetic and Dielectric Anomalies in Rare‐Earth‐Substituted BiFeO3 Ceramics

In this work, we report on the magnetic and dielectric anomalies observed in dense Bi_1–xRE_xFeO₃ ceramics (RE = Dy, Tb; 0 ≤ x ≤ 0.3) at cryogenic temperatures. For compositions with a high content of rare‐earth ions, thermomagnetic experiments revealed a distinct anomaly in the magnetization curves at temperatures below 200 K. The temperature of the magnetic anomaly along with a thermal hysteresis was found to be dependent on the rare‐earth concentration and magnetic field strength. Low‐temperature dielectric measurements showed an anomalous relaxor‐like behavior of the relative permittivity and dielectric loss in highly doped ceramic samples. The anomalies in low‐temperature magnetization and dielectric response are suggested to result from the presence of GdFeO₃‐like orthoferrite phase and/or bismuth rare‐earth‐mixed iron garnet impurities.     

Piezoelectric properties of (Na0.5K0.5)(Nb1‐xSbx)O3‐SrTiO3 ceramics with tetragonal‐pseudocubic PPB structure

CuO‐added 0.96(Na_0.5K_0.5)(Nb_1‐xSb_x)O₃‐0.04SrTiO₃ ceramics sintered at the low temperature of 960°C for 10 hours showed dense microstructures and high relative densities. The specimens with 0.0 ≤  x ≤ 0.04 had orthorhombic‐tetragonal polymorphic phase boundary (PPB) structure. Tetragonal‐pseudocubic PPB structure was observed in specimens with 0.05 ≤  x ≤ 0.07, while the specimen with x = 0.08 has a pseudocubic structure. The structural variation in the specimens is explained by the decreases in the orthorhombic‐tetragonal transition temperature and Curie temperature with the addition of Sb⁵⁺ ions. The specimens with 0.05 ≤  x ≤ 0.07, which have tetragonal‐pseudocubic PPB structure, had large electric field‐induced strains of 0.14%‐0.016%. Moreover, these specimens also showed increased d₃₃ values between 280 pC/N and 358 pC/N. In particular, the specimen with x = 0.055 showed particularly enhanced piezoelectric properties: d₃₃ of 358 pC/N, k_p of 0.45, and the electric field‐induced strain of 0.16% at 4.5 kV/mm.     

Structure Stability and Microwave Dielectric Properties of (1 − x) Ba(Mg1/2W1/2) O3 + xBa(Y2/3W1/3)O3 Ceramics

The structure stabilities of double perovskite ceramics‐ (1 ? x) Ba(Mg_1/2W_1/2)O₃ + xBa(Y_2/3W_1/3)O₃ (0.01 ≤ x ≤ 0.4) have been studied by X‐ray powder diffraction (XRD), scanning electron microscopy (SEM), and Raman spectrometry in this study. The microwave dielectric properties of the ceramics were studied with a network analyzer at the frequency of about 8–11 GHz. The results showed that all the compounds exhibited face‐centered cubic perovskite structure. Part of Y³⁺ and W⁶⁺ cations occupied 4a‐site and the remaining Y³⁺ and Mg²⁺ distributed over 4b‐site, respectively, and kept the B‐site ratio 1:1 ordered. Local ordering of Y³⁺/Mg²⁺ on 4b‐site and Y³⁺/W⁶⁺ cations on 4a‐site within the short‐range scale could be observed with increasing Y‐doping content. The decomposition of the double perovskite compound at high temperature was successfully suppressed by doping with Y on B‐site. However, Ba₂Y_0.667WO₆ impurity phase appeared when x > 0.1. The optimized dielectric permittivity increased with the increase in Y doping. The optimized Q × f value was remarkably improved with small amount of Y doping (x ≤ 0.02) and reached a maximum value of about 160 000 GHz at x = 0.02 composition. Further increasing in Y doping led to the decrease in Q × f value. All compositions exhibited negative τ_f values. The absolute value of τ_f decreased with increasing Y‐doping content. Excellent combined microwave dielectric properties with ε_r = 20, Q × f = 160 000 GHz, and τ_f = ?21 ppm/°C could be obtained for x = 0.02 composition.     

Synthesis,structural characterization,and photoluminescence properties of Eu3+‐doped Mg3‐xEux(BO3)2 phosphor

Eu³⁺‐doped Mg_3‐xEu_x(BO₃)₂ (x = 0.000, 0.005, 0.010, 0.020, 0.050, and 0.100) phosphors were synthesized for the first time by solution combustion synthesis method, which is a fast synthesis method for obtaining nano‐sized borate powders. The optimization of the synthesis conditions of phosphor materials was performed by TG/DTA method. These phosphors were characterized by XRD, FTIR, SEM‐EDX, and photoluminescence, PL analysis. The XRD analysis exhibited that all of the prepared ceramic compounds have been crystallized in orthorhombic structure with space group Pnnm. Also, the influence of europium dopant ions on unit cell parameters of host material was analyzed using Jana2006 program and the crystalline size was determined by Debye‐Scherrer's formula. The luminescence properties of all Eu³⁺‐doped samples were investigated by excitation and emission spectra. The excitation spectra of Mg_3‐xEu_x(BO₃)₂ phosphors show characteristic peak at 420 nm in addition to other characteristic peaks of Eu³⁺ under emission at 613 nm. The emission spectra of Eu³⁺‐doped samples indicated most intensive red emission band dominated at 630 nm belonging to ⁵D₀→⁷F₂ magnetic dipole transition. Furthermore, the optimum or quenching concentration of Eu³⁺ ion has been determined as x = 0.010 showed the maximum emission intensity when it was excited at 394 nm.     

Copper‐substituted spinel Zn‐Mg ferrite nanoparticles as potential heating agents for hyperthermia

Cu_xZn_0.5‐xMg_0.5Fe₂O₄ (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrite nanoparticles are synthesized via thermal treatment technique using polyvinyl alcohol (PVA) as a capping agent. The effect of Cu²⁺ ions substitution on the magnetic and structural properties of ZnMg ferrite nanoparticles is assessed. X‐ray diffraction (XRD) results prove the formation of spinel cubic ferrite with nanocrystalline structure. It is observed by increasing Cu²⁺ ions content in Cu²⁺‐substituted ZnMg ferrite samples, the lattice constant decreases. The field‐emission scanning electron microscopy (FESEM) micrographs indicate that all samples have sizes in nanometer scale with almost spherical morphology and ZnMg ferrite nanoparticles size is increased as the result of Cu²⁺ substitution. Magnetic data show that by increasing in Cu²⁺ content, the saturation magnetization (Ms) increases up to x = 0.3 and then declines with the addition of more Cu²⁺ ions in the samples. To assess the heat release of Cu²⁺‐substituted ZnMg ferrite nanoparticles, an alternating magnetic (AC) field is applied. The results show an upward trend for the samples in the temperature vs time chart, as a result of increasing in Ms of the samples. The Cu_0.3Zn_0.2Mg_0.5Fe₂O₄ sample exhibits a temperature increase up to 43°C during 510 seconds in the exposure of 125 Oe magnetic field intensity. The cell compatibility of the samples is investigated using osteoblast‐like cells (MG63). Results show that the substitution of Cu²⁺ significantly affects the cell compatibility of the ZnMg ferrite nanoparticles.     

Effect of Ni2+ substitution on structural,magnetic, dielectric and optical properties of mixed spinel CoFe2O4 nanoparticles

Nanoparticles of Co_1−xNi_xFe₂O₄ with x=0.0, 0.10, 0.20, 0.30, 0.40 and 0.50 were synthesized by co-precipitation method. The structural analysis reveals the formation of single phase cubic spinel structure with a narrow size distribution between 13–17 nm. Transmission electron microscope images are in agreement with size of nanoparticles calculated from XRD. The field emission scanning electron microscope images confirmed the presence of nano-sized grains with porous morphology. The X-ray photoelectron spectroscopy analysis confirmed the presence of Fe²⁺ ions with Fe³⁺. Room temperature magnetic measurements showed the strong influence of Ni²⁺ doping on saturation magnetization and coercivity. The saturation magnetization decreases from 91 emu/gm to 44 emu/gm for x=0.0–0.50 samples. Lower magnetic moment of Ni²⁺ (2 µ_B) ions in comparison to that of Co²⁺ (3 µ_B) ions is responsible for this reduction. Similarly, overall coercivity decreased from 1010 Oe to 832 Oe for x=0.0–0.50 samples and depends on crystallite size. Cation distribution has been proposed from XRD analysis and magnetization data. Electron spin resonance spectra suggested the dominancy of superexchange interactions in Co_1−xNi_xFe₂O₄ samples. The optical analysis indicates that Co_1−xNi_xFe₂O₄ is an indirect band gap material and band gap increases with increasing Ni²⁺ concentration. Dispersion behavior with increasing frequency is observed for both dielectric constant and loss tangent. The conduction process predominantly takes place through grain boundary volume. Grain boundary resistance increases with Ni²⁺ ion concentration.     

The Nanocrystalline SnO2–TiO2 System—Part I: Structural Features

The phases present and their crystal structure and microstructure in the nanocrystalline SnO₂–TiO₂ system were studied in the compositional range Sn_1?xTi_xO₂ (0.0 ≤ x ≤ 0.9). There is an apparent increase in the solubility limits in the solid solution compared to bulk crystalline SnO₂–TiO₂. No two phase region was observed with increasing TiO₂ content. Electron energy loss spectroscopy, infrared spectroscopy (FTIR), and X‐ray diffraction (XRD) of the nanopowders showed that the apparent increase in solubility is related to the systematic Ti⁴⁺ segregation on the particle surface (surface excess) at the SnO₂‐rich side, avoiding the nucleation of a second phase even at high Ti⁴⁺ contents. Is this finding in accord with Raman spectra, which suggest localized Ti‐rich sites in the absence of a second crystalline phase. Ti⁴⁺ surface excess is also lead to a modification of the surface hydroxyls and a decrease in the crystallite size of the nanoparticles (with a concomitant increase in surface area), with expected implications to catalytic and sensorial properties of these nanoparticles.     

Structural Investigation and Functional Properties of MgxNi1−xFe2O4 Ferrites

The preparation, structural, microstructural, dielectric, and low temperature magnetic properties of Mg_xNi_1?xFe₂O₄ (x = 0, 0.17, 0.34, 0.50, 0.66, 0.83, 1) ferrites synthesized by using a self‐combustion sol–gel method is presented. Good insulating properties were found for all the compositions at high frequencies (kHz and MHz range), which might drive the present ceramics as interesting for RF/microwaves applications. By increasing the Mg²⁺ concentration, the total resistivity strongly increases (from ~10⁶ Ωm for the Ni ferrite to 10⁹ Ωm for the Mg ferrite), corresponding to conductivities in the range 10^?9–10^?6 S/m at f = 1 Hz. Typical ferrimagnetic character with a small coercivity and saturation magnetization in the range (30–50) Am²/kg, which slightly decreases with increasing the Mg content, were found. On the basis of the combined results from the infrared spectroscopy and XRD analysis, it was shown that the magnetic properties depend on the Mg²⁺ ions distribution on the octahedral and tetrahedral sites and the experimental saturation magnetization allowed to compute the cation distribution for the Mg_xNi_1?xFe₂O₄ ferrites.     

Order–Disorder Phase Transition and Magneto‐Dielectric Properties of (1−x)LiFe5O8–xLi2ZnTi3O8 Spinel‐Structured Solid Solution Ceramics

In this study, the spinel solid solution ceramics (1?x)LiFe₅O₈–xLi₂ZnTi₃O₈ (0 ≤ x ≤ 1) were prepared via the solid‐state reaction method. The phase evolution, sintering behaviors, microstructures, magneto‐dielectric properties, and microwave dielectric properties were systematically investigated. The XRD and SEM analysis indicated that the LiFe₅O₈ phase and the Li₂ZnTi₃O₈ phase were almost fully soluble in each other at any proportion. Meanwhile, the evidence of ionic substitution has been directly observed at the atomic scale by means of scanning transmission electron microscopy, which is further confirmed by the Raman spectroscopy. Evidence shows that the magnetic and dielectric properties are quite sensitive to the compositions. The optimal results with remarkable magneto‐dielectric properties of μ′ = 38.2, tanδ_μ = 0.25, ε′ = 19.6, tanδ_ε = 8 × 10^?3 at 1 MHz, and ε′ = 19.1, Q × f = 10 400 GHz at about 7 GHz have been obtained in 0.25LiFe₅O₈–0.75Li₂ZnTi₃O₈ sample. The design of complex spinel solid solution can generate novel magneto‐dielectric single‐phase ceramics combining both high permeability and good dielectric properties, which provides a way in developing multifunctional materials for applications in electronic devices.     

Electrical properties of Y/Mg modified NiO simple oxides for negative temperature coefficient thermistors

The semiconductors based on simple oxide have unique features with controllable electrical property by element doping. Y³⁺ doped NiO (Ni_1−xY_xO, x ≤ 0.01) and Mg²⁺ substituted Ni_0.995Y_0.005O (Ni_0.995−yY_0.005Mg_yO, y ≤ 0.5) powders were synthesized by a wet chemical method. The related ceramics were obtained by conventional ceramic processing. Phase component, microstructure, electrical property and temperature sensitivity of the prepared ceramics were investigated. All ceramics have a rock-salt type crystalline structure. The room-temperature resistivity of the ceramics can be widely adjusted from 254 to 12 322 Ω·cm by changing the concentrations of Y³⁺ and Mg²⁺ ions. The samples show typical characteristics of negative temperature coefficient of resistivity and have high temperature sensitivity with material constants higher than 4745 K. The analysis of impedance spectra indicates that the electrical properties resulted from both grain effect and grain boundary effect. Both band conduction and small polaron hopping were proposed as possible conduction mechanisms in the studied ceramics.     

Phase Evolution and Microstructural Studies in CaZrTi2O7–Nd2Ti2O7 System

A series of compositions with general stoichiometry Ca_1?xZr_1?xNd_2xTi₂O₇ has been prepared by high‐temperature solid‐state reaction of component oxides and characterized by powder X‐ray diffraction and electron probe for microanalyses (EPMA). The phase fields in CaZrTi₂O₇–Nd₂Ti₂O₇ system and distribution of ions in different phases have been determined. Four different phase fields, namely monoclinic zirconolite, cubic perovskite, cubic pyrochlore, and monoclinic Nd₂Ti₂O₇ structure types are observed in this system. The 4M‐polytype of zirconolite structure is stabilized by substitution of Nd³⁺ ion. The addition of Nd³⁺ ions form a cubic perovskite structure‐type phase and thus observed in all the compositions with 0.05 ≤ x ≤ 0.80. Cubic pyrochlore structure‐type phase is observed as a coexisting phase in the nominal composition with 0.20 ≤ x ≤ 0.90. Only a subtle amounts of Ca²⁺ and Zr⁴⁺ are incorporated into the perovskite‐type Nd₂Ti₂O₇ structure. EPMA analyses on different coexisting phases revealed that the pyrochlore and perovskite phases have Nd³⁺‐rich compositions.     

Structure‐Dependent Microwave Dielectric Properties and Middle‐Temperature Sintering of Forsterite (Mg1–xNix)2SiO4 Ceramics

The crystal structure, microstructure, and microwave dielectric properties of forsterite‐based (Mg_1–xNi_x)₂SiO₄ (x = 0.02–0.20) ceramics were systematically investigated. All samples present a single forsterite phase of an orthorhombic structure with a space group Pbnm except for a little MgSiO₃ secondary phase as x > 0.08. Lattice parameters in all axes decrease linearly with increasing Ni content due to the smaller ionic radius of Ni²⁺ compared to Mg²⁺. The substitution of an appropriate amount of Ni²⁺ could greatly improve the sintering behavior and produce a uniform and closely packed microstructure of the Mg₂SiO₄ ceramics such that a superior Q × f value (152 300 GHz) can be achieved as x = 0.05. The τ_f value was found to increase with increasing A‐site ionic bond valences. In addition, various additives were used as sintering aids to lower the sintering temperature from 1500°C to the middle sintering temperature range. Excellent microwave dielectric properties of ε_r~6.9, Q × f~99800 GHz and τ_f~?50 ppm/°C can be obtained for 12 wt% Li₂CO₃‐V₂O₅‐doped (Mg_0.95Ni_0.05)₂SiO₄ ceramics sintered at 1150°C for 4 h.     

Low‐Temperature Sintering and Microwave Dielectric Properties of CaMoO4‐Based Temperature Stable LTCC Material

The CaMoO₄–xY₂O₃–xLi₂O ceramics were prepared by the solid‐state reaction method. The sintering behavior, phase evolution, microstructure, and microwave dielectric properties were investigated. CaMoO₄ solid solution was obtained when x = 0.030, and two‐phase system including tetragonal CaMoO₄ phase and cubic Y₂O₃ phase formed when 0.066 ≤ x ≤ 1.417. A temperature stable CaMoO₄‐based microwave dielectric ceramic with ultralow sintering temperature (775°C) was obtained in the CaMoO₄–xY₂O₃–xLi₂O system when x = 0.306, which showed good microwave dielectric properties with a low permittivity of 9.5, a high Q_f value of 63 240 GHz, and a near‐zero temperature coefficient of resonant frequency of +7.2 ppm/°C.     

Dielectric and Raman Spectroscopic Studies of Na0.5Bi0.5TiO3–BaSnO3 Ferroelectric System

A series of lead‐free perovskite solid solutions of (1 ? x) Na_0.5Bi_0.5TiO₃(NBT)—x BaSnO₃(BSN), for 0.0 ≤ x ≤ 0.15 have been synthesized using a high‐temperature solid‐state reaction route. The phase transition behaviors are studied using dielectric and Raman spectroscopic techniques. The ferroelectric to relaxor phase transition temperature (T_FR) and the temperature corresponding to maximum dielectric permittivity (T_m) are estimated from the temperature‐dependent dielectric data. Dielectric studies show diffuse phase transition around ~335°C in pure NBT and this transition temperature decreases with increase in x. The disappearance of x‐dependence of A₁ mode frequency at ~134 cm^?1 for x ≥ 0.1 is consistent with rhombohedral‐orthorhombic transition. In situ temperature dependence Raman spectroscopic studies show disappearance and discontinuous changes in the phonon mode frequencies across rhombohedral (x < 0.1)/orthorhombic (x ≥ 0.1) to tetragonal transition.     

Doping and luminescence mechanisms of broadband NIR-II emitting Zn2(1−x)Ni2xGa3Ge0.75O8 nanoparticles

In this study, Zn_2(1−x)Ni_2xGa₃Ge_0.75O₈ (x = 0.0002, 0.001, 0.002, 0.010, 0.020, and 0.030) nanoparticles with broadband NIR-II emissions were synthesized by a hydrothermal synthesis combined with a vacuum annealing. For the Ni²⁺-doped ZGGO samples (x = 0–0.03), with increasing concentration, the particle shape gradually becomes spherical and the average particle size decreases from 124.4 to 74.2 nm. Meanwhile, for the ZGGO:Ni²⁺_0.01 nanoparticles, the asymmetrically broad emission peak around 1290 nm, which is the superposition of the two peaks locating at 1280 and 1450 nm, can be observed and the afterglow time exceeds 30 min. Based on the spectral data, luminescence decay curves, first-principles calculations, and Tanabe–Sugano theory, it is found that Ni²⁺ ions can occupy not only tetrahedral but also octahedral Zn²⁺ sites (locating in anti-site defects pair) in the spinel ZGGO host, and they have the contributions to the 1450 and 1280 nm emission peaks, respectively. Furthermore, the surface-modified ZGGO:Ni²⁺ nanoparticles exhibited good stability in the H₂O and HSA (5% human serum albumin, pH = 7.4) solutions and the occurred agglomeration sinking in the SLS (simulate lysosomal solution, pH = 4.7) solution. Compared to the narrow-band NIR-II emitting persistent luminescence nanoparticles (ZGGO:Cr³⁺,Er³⁺ and ZGGO:Cr³⁺,Nd³⁺), broadband NIR-II emitting persistent luminescence nanoparticles (ZGGO:Ni²⁺ NIR-II) possess stronger persistent luminescence intensity and can effectively avoid the water absorption of biological tissues. Our results suggest that ZGGO:Ni²⁺ persistent luminescence nanoparticles have a potential to become optical probes for deep-tissue autofluorescence-free bioimaging in the biomedical field.     

Investigation of luminescence properties of Pb2+‐doped Sr2B2O5 phosphor

A near‐UV emitting phosphor, Pb²⁺‐doped Sr₂B₂O₅ was synthesized by the solid‐state reaction method at 900°C for 3 hours in air. The structure of the phosphor was verified by X‐ray diffraction study which shows monoclinic phase. Fourier transform infrared (FTIR) analysis confirmed the formation of Sr₂B₂O₅. The excitation and emission spectra of the synthesized phosphors were investigated at room temperature with photoluminescence spectrophotometer. The emission and excitation bands of Pb²⁺‐doped Sr₂B₂O₅ were observed at 370 and 289 nm, respectively. The dependence of the PL intensities on the Pb²⁺ concentration for the Sr_2?xPb_xB₂O₅ (0.01 ≤ x ≤ 0.03) phosphors was studied and it was observed that the concentration quenching of Pb²⁺ in Sr₂B₂O₅ is 0.025 mol.