Magnetic and antibacterial studies of sol-gel dip coated Ce doped TiO2 thin films: Influence of Ce contents

Ce-doped TiO₂ thin films were synthesized by sol-gel dip coating route to evaluate the effect of Ce doping percentage on properties of TiO₂. X-ray diffraction spectra revealed both anatase and brookite phases, and Ce doping favours the anatase–brookite transformation of TiO₂ films. The optical constants of the thin films were achieved by evaluating spectroscopic UV-VIS-NIR spectrophotometry data. The band gap of the Ce doped TiO₂ was reduced from ~3.93 eV to ~3.79 eV with an increase in Ce doping percentage. All films have shown ferromagnetic behaviors which increase with the increase in Ce content due to enhancement in the bound magnetic polaron. Higher Ce doping increases the oxygen vacancies and saturation magnetization. Boost magnetic properties stem from the generation of the interaction between the Ce ion and an oxygen vacancy. The study showed that the antimicrobial activity of Ce doped TiO₂ is ineffective. Hence doping of Ce can modify the properties of TiO₂ and are used in LEDs, magneto-optical devices and solar cells.     

Defect induced magnetic transition in Co doped CeO2 sputtered thin films

Cobalt-doped cerium dioxide thin films exhibit room temperature ferromagnetism due to high oxygen mobility in doped CeO₂ lattice. CeO₂ is an excellent doping matrix as there is a possibility of it losing oxygen while retaining its structure. This leads to increased oxygen mobility within the fluorite CeO₂ lattice, leading to formation of Ce³⁺ and Ce⁴⁺ species. Magnetic ceria materials are important in several applications from magnetic data storage devices to magnetically recoverable catalysts. In this paper, the room temperature ferromagnetism of rf sputtered Co doped CeO₂ thin films is reported whereas undoped CeO₂ thin films exhibit paramagnetic behavior. The ferromagnetic properties of the Co doped films were explained based on oxygen vacancies created by Co ions in Ce sites. This is further supported by X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) and Raman. Change in surface morphology due to Co doping of the samples were analyzed using atomic force microscopy (AFM).     

Effect of Ce-doping on microstructure and electrical properties of LaAlO3 ceramics

A series of novel negative temperature coefficient (NTC) thermistor materials based on La_1-xCe_xAlO₃ (0 ≤ x ≤ 0.2) ceramics were synthesized via the solid-state route. X-ray diffraction results confirmed the successful doping of Ce in the La_1-xCe_xAlO₃ crystal and the formation of a good solid solution. Scanning electron microscopy results indicated that Ce doping is beneficial for grain growth and reduces the porosity of the samples. With the increase in the Ce doping amount, the average grain size increased from 2.1793 to 10.7344 μm, and densities of the ceramics increased from 93.15% to 99.26%. The temperature vs resistance curve indicated that Ce doping reduces the resistivity of LaAlO₃ materials, while reducing the B_200/1400 value of the LaAlO₃ ceramic. For a doping amount of 0.2, the B_200/1400 value of the LaAlO₃ ceramic decreased from 18175.1 to 4897.7K, and the resistivity at 1000 °C decreased from 68971.87 to 1105.15 Ω cm. In addition, the La_1-xCe_xAlO₃ (0 ≤ x ≤ 0.2) series materials exhibited good linear NTC characteristics. X-ray photoelectron spectroscopy results revealed that the resistivity of the LaAlO₃ materials decreased after Ce doping owing to the transformation between the Ce⁴⁺ and Ce³⁺ valence states，and the concentration of Ce³⁺ increased with the increase in the Ce doping amount. Ce³⁺ increases the concentration of oxygen vacancies, decreasing the resistance. Impedance analysis findings suggested that the resistance of the La_1-xCe_xAlO₃ (0 ＜ x ≤ 0.2) material mainly originates from the grain. These results indicate that Ce doping is an effective method to reduce the resistivity of LaAlO₃. Consequently, La_1-xCe_xAlO₃ (0 ≤ x ≤ 0.2) is a promising material for NTC applications.     

New Magneto‐Optical Film of Ce,Ga:GIG with High Performance

Ce³⁺‐doped Gd₃Fe₅O₁₂ (Ce:GIG) film has a good application prospect in the field of integrated optical device. In this article, Ce:GIG and Ce,Ga:GIG films were deposited onto the quartz glass substrate by using radio‐frequency magnetron sputtering technology. The crystal phase, surface morphology, magnetization, and magnetic circular dichroism properties of films were characterized by using the X‐ray powder diffraction, atomic force microscopy, vibrating sample magnetometer, and circular dichroism spectrometer. The results show that as‐prepared Ce,Ga:GIG films has a good quality and show an excellent magneto‐optical performance, and the doping of Ga³⁺ ion and the annealing process have significant effect on the magnetism and magneto‐optical performances. It is expected that Ce,Ga:GIG film with a moderate Ga³⁺‐doping content is a better candidate than Ce:GIG and Ce:YIG films for the next generation of integrated optical isolator and other magneto‐optical equipment.     

Effect of Ce dopant on upconversion and temperature sensing performances in homogeneous ultrasmall Y2O3:Yb3+/Ho3+ nanoparticles through flame aerosol synthesis

Flame aerosol synthesis (FAS) is an excellent strategy for continuous, fast, and mass production of small-size upconversion nanoparticles (UCNPs), which have high potential applications in fields like biological imaging, colour display and optical temperature sensing. However, flame-made UCNPs have received less attention, and relevant studies are limited. Herein, for the first time, we successfully fabricated cerium (Ce)-doped homogeneous ultrasmall Y₂O₃:Yb³⁺/Ho³⁺ UCNPs using a liquid-fed FAS method. Ce was doped to improve the upconversion luminescence (UCL) of the Y₂O₃:Yb³⁺/Ho³⁺ UCNPs. The overall UCL intensity was enhanced ～77.9-fold for an optimal concentration of 20 mol% Ce-doped UCNPs, compared with the UCNPs without Ce doping with a relatively homogeneous ultrasmall size of 8–10 nm. Further studies confirmed that both trivalent (Ce³⁺) and tetravalent (Ce⁴⁺) simultaneously exist in the Y₂O₃ hosts and are critical in enhancing the UCL properties. In addition, the fluorescence intensity ratio (FIR) method was used to evaluate the thermal properties of the fabricated UCNPs. Ce doping significantly improved the thermal sensitivity of Y₂O₃:Yb³⁺/Ho³⁺ UCNPs. An excellent relative sensitivity (S_R) of 0.622% K^?1 at 598 K was obtained for flame-made UCNPs doped with 20 mol% Ce.     

Ce/Mn/Cr: Y3Al5O12 phosphor ceramics for white LED and LD lighting with a high color rendering index

Ce/Mn/Cr: Y₃Al₅O₁₂ transparent ceramics with a pure garnet structure and a high color rendering index were prepared by a solid-state reaction method. Mn²⁺ and Cr³⁺ enhance the emission between 500 and 700 nm and expand the conventional Ce: YAG phosphors spectrum. The Ce³⁺ can work both, as activators and sensitizers, and the intense energy transfer from Ce³⁺ to Mn²⁺/Cr³⁺ is realized through the non-radiative and radiative processes. In the sample with the optimized doping concentration the high color rendering index (CRI) value of 75.3 can be achieved under a 450 nm laser diode excitation. The chromaticity coordinates can be tuned from (0.3125, 0.3232) to (0.2917,0.2851) by varying the doping concentration. With the increasing Mn²⁺/Cr³⁺ doping concentration, the lifetime of Ce³⁺, quantum efficiency and luminous efficiency are all gradually decreased. This work effectively offers a scheme for realizing the high color rendering performance of phosphor-converted transparent ceramics in white LEDs/LDs.     

Abnormal Curie temperature behavior and enhanced strain property by controlling substitution site of Ce ions in BaTiO3 ceramics

Dopants have a great effect on the phase transition behavior and the properties of the ferroelectrics. Here we report an abnormal Curie temperature (T_c) behavior and enhanced strain property by controlling the doping site of Ce ions in the BaTiO₃ ceramics. The Ce doped A-site and B-site BaTiO₃ ceramics (BT-xCe-A and BT-xCe-B, x=2, 4, 6, 8 mol%) were prepared by a conventional solid state reaction method through a different sintering temperature. The Raman test and the XPS results give evidence that Ce is successfully incorporated into Ba-site as Ce³⁺ in the BT-xCe-A samples, and into Ti-site as Ce⁴⁺ in the BT-xCe-B samples. Different doping sites have distinct phase transition behavior. Compared with the BT-xCe-A ceramics, the BT-xCe-B ceramics show higher T_c, and the T_c show abnormal increasing behavior with the increase of the Ce content. In the Ce doped BaTiO₃ system, this phenomenon has not been reported before. The origin of the higher T_c and its increasing behavior is discussed from the viewpoint of the larger local strain field generated by the Ce⁴⁺ ions entering into B-site. Besides, the BT-xCe-B ceramics show a stronger diffuse phase transition behavior. The reason is considered that the Ce substituting B-site leads to a multiphase coexistence, which induces more frustration states for the polarization according to the random defect field theory. Due to such distinct phase transition behavior, the BT-xCe-B ceramics show the enhanced maximum polarization (P_max) and enhanced strain properties compared with the BT-xCe-A ceramics. This work may provide a promising way to design high performance materials by controlling the substituting site of the dopant in other lead-free systems.     

Optical Performances of YAG:Re3+ (Re = Ce,Eu) Phosphor Films with Co‐Doping Tb3+ as Energy‐Transfer Sensitizer

The paper investigates the effect of co‐doping Tb³⁺ as an energy‐transfer sensitizer on optical properties of YAG:Re³⁺ (where, Re = Ce, Eu) phosphor films synthesized by sol–gel route. The results suggest that, Tb³⁺ is a promising sensitizer for improving the optical performances of the as‐prepared YAG:Re³⁺ films, and a Tb³⁺ co‐doping concentration of 20% was found to be an optimum level on account of Tb³⁺ concentration quenching. Due to the energy‐transfer processes of Tb³⁺→Re³⁺, the as‐prepared Y_0.8 Tb_0.2AG:Re³⁺ films displayed strong abilities of absorption in the ultraviolet (UV) light range, and bright green–yellow emission for YAG:Ce³⁺ or red emission for YAG:Eu³⁺ under 275 nm irradiation, which could be utilized for UV‐excited WLED and display applications.     

Structural analysis and electrode performance of Ce doped SrMnO3 synthesised by EDTA citrate complexing process

Abstract

Sr_1?xCe_xMnO₃ (SCM, 0·1≤x≤0·4) powders were synthesised by an ethylenediaminetetraacetic acid citrate complexing process, and their properties were investigated. The synthesised Sr_1?xCe_xMnO₃ powders showed a pure perovskite phase, whereas the composition with x?=?0·4 had second phases. The unit cell volumes increased with increasing Ce content because substituted Ce ions formed some Mn³⁺ ions, which have a larger ionic radius than Mn⁴⁺. The electrical conductivity improved with increasing Ce content up to x?=?0·3 (291 S cm^?1 at 750°C), revealing a double exchange interaction. Although the electrical conductivity was increased by doping Ce ions, the polarisation resistance increased due to the increase in lattice distortion with doping Ce content. The substitution of Ce ions for Sr in SrMnO₃ led to the formation of larger Mn³⁺ ions than Mn⁴⁺ ions and lattice distortion, which would affect the electrical and oxygen ion conductivity.     

Cerium-doped LaSi3N5: Computed electronic structure and band gaps

First-principle calculations are performed using VASP to enhance the understanding of the electronic structure of stoichiometric LaSi₃N₅ and Ce-doped LaSi₃N₅. Electronic structure and band gaps are calculated using DFT and the screened Coulomb hybrid functional HSE06. Five doping schemes are investigated: La³⁺/^*Ce³⁺, La³⁺/□ (□ = cation vacancy), La³⁺/Ce³⁺, La³⁺/Ce²⁺ compensated by one framework N³⁻/O²⁻ substitution, and combined La³⁺/Ce³⁺and La³⁺/□ substitutions. The vacancy is electronically balanced by N³⁻/O²⁻ substitutions. Two pseudopotential files for Ce^III are used to investigate the effect of f orbitals on the calculated band gap. There was no change in the calculated value of the band gap using DFT method for the ^*Ce^III doped LaSi₃N₅ compared to the stoichiometric LaSi₃N₅ (3.15 eV). HSE06 provided more precise band gaps. The calculated band gap of Ce-doped LaSi₃N₅ is 4.65 eV with the possible electronic transitions from Ce spin-up 4f to Ce spin-up 4f states, or La 5d states..     

Electrochemical properties of Sr1−xCexMnO3 (0.1≤x≤0.4) – GDC composite cathodes for IT-SOFCs

The electrochemical properties of Sr_1−xCe_xMnO₃ (SCM, 0.1≤x≤0.4)–Gd_0.2Ce_0.8O_2−x (GDC) composite cathodes were determined by impedance spectroscopy. The study focused on the doping effect of Ce in the composite cathodes. Single-phase perovskite was obtained for 0.1≤x≤0.3 in SCM. No reaction occurred between the Sr_0.7Ce_0.3MnO₃ electrode and the GDC electrolyte at an operating temperature of 800 °C for 100 h. In the single phase perovskite region, lattice expansion occurred due to the reduction of Mn⁴⁺ to Mn³⁺ at B-sites, and this was attributed to an increase in Ce content. Ce doping enhanced the electrode performance of SCM–GDC composite cathodes, and best electrode performance was achieved for the Sr_0.7Ce_0.3MnO₃–GDC composite cathode (0.93 Ω cm² and 0.47 Ω cm² at 750 °C and 800 °C, respectively). The improvement in electrode performance was attributed to increases in charge carriers induced by a shift of some Mn from +4 to +3 and to the formation of surface oxygen vacancies caused by Mn⁴⁺ to Mn³⁺ conversion at high temperatures.     

The effect of Lu3+ doping upon YAG:Ce phosphor ceramics for high-power white LEDs

Intense green emission is extremely significant to the color rendering index (CRI) of white LEDs. Various green-emitting YLuAG:Ce phosphor ceramics were successfully prepared by vacuum sintering. The effects of Lu³⁺ doping on structure and luminescence property were investigated in detail. In comparison with YAG:Ce, YLuAG:Ce ceramics own smaller grain size, better luminescence performance and higher thermal stability. The photoluminescence (PL) intensity of YLuAG:Ce ceramics increases by 23.6 % due to the “light scattering enhanced effect”. Furthermore, the Ce³⁺ emission is obviously blue-shifting from 533 nm to 519 nm, and the intensity of YLuAG:Ce ceramics reduces only about 8.9 % at 250 °C, showing better thermal stability (vs 11.1 % of YAG:Ce). The LE of LED packaged by YLuAG:Ce ceramic is up to 148.88 lm/W when the doping Lu³⁺ y is 2.1. The above results show that tailored YLuAG:Ce phosphor ceramic is a potential green-emitting color converter for high-power LEDs (hp-LEDs).     

Luminescent and magnetic properties of cerium-doped yttrium aluminum garnet and yttrium iron garnet composites

Functional materials exhibiting magnetic and luminescent properties have been recognized as an emerging class of materials with great potential in advanced applications. Herein, properties of multifunctional ceramic composites consisting of two garnets, luminescent cerium-doped Y₃Al₅O₁₂ (Ce:YAG) and magnetic Y₃Fe₅O₁₂ (YIG), are reported. On increasing the sintering temperature, both the photoluminescence and saturation magnetization of the Ce:YAG-YIG composites decreased gradually because of the interdiffusion of trivalent ions such as Al³⁺ and Fe³⁺. At a constant sintering temperature of 1100?°C, the YIG contents in the composites increased, thereby causing their luminescent properties to degrade and the saturation magnetizations to increase. For application to electronics, Ce:YAG-YIG composite thin films were integrated on quartz substrates by sputtering the ceramic target. The composite thin films exhibited both magnetic and luminescent properties after annealing. These techniques facilitate the incorporation of multifunctional nanocomposites into various devices.     

Oxygen vacancy luminescence and band gap narrowing driven by Ce ion doping with variable valence in SnO2 nanocrystals

Although considerable research works have witnessed the important modulations of oxygen vacancies on the optical, electrical, and magnetic properties of SnO₂ nanostructures, it is not easy to control oxygen vacancy defects in such systems.The difficulty stems from that oxygen vacancy is a kind of atomic defect, and its distribution is sensitive to process conditions and external factors, which makes direct characterization and purposeful control difficult. The purpose of this work on Ce-doped SnO₂ nanocrystals is to investigate the tolerance of the host lattice to Ce ions, the population and evolution of Ce³⁺/Ce⁴⁺ ions, and the possibility to adjust oxygen vacancies by Ce³⁺ ions, and then focus on the influence of oxygen vacancy defects on the band gap and luminescence performance. As Ce doping concentration increases from 0 to 12 at.%, the doped system changes from Ce³⁺ dominated at low doping amount (≤3 at.%) to Ce³⁺/Ce⁴⁺ coexistence at medium doping concentration (3 at.% ∼ 9 at.%), to occurrence of CeO₂ impurity phase at over doping (∼12 at.%). The optimum doping occurs at 6 at.%, which corresponds to the saturated critical point of Ce³⁺ content and the maximum oxygen vacancy concentration. Importantly, the oxygen vacancies in the current Ce-doped SnO₂ nanocrystals is directly regulated by the Ce³⁺ ion concentration on the Sn sites, which plays an important role in the band gap tuning and visible light emission. With Ce concentration increasing from 0 to 12 at.%, the band gap monotonicity decreases from 3.36 eV to 3.12 eV, while the intensity of the oxygen vacancy luminescence band first increases and then decreases, with the turning point at 6 at.%. Both band gap narrowing effect and enhanced emission indicate that Ce-doped SnO₂ should be a promising method to design and manufacture visible light responsive SnO₂ based optoelectronic materials by manipulating oxygen vacancy defects.     

Effect of Sm doping on structure,dielectric and magnetic properties of GdFeO3

Nano-particles of GdFeO₃ (GFO) and Gd_0.4Sm_0.6FeO₃ (GSFO) were synthesized by sol-gel auto-combustion method to study the effect of Sm³⁺doping on physical properties of GFO. Rietveld refinement of x-ray diffraction pattern confirms the proper phase formation of samples and the average octahedral <Fe–O1–Fe> angle of GSFO is found to be 145.54⁰ which is larger compared to GFO 142.53⁰. Temperature dependent DC magnetization measurements showed that Sm doping in GdFeO₃introduces spin-reorientation transition which is absent in pure GdFeO₃ phase. The dielectric constant of GSFO is found to be larger than that of GFO because of change in hybridization between the O-2p states and Fe-3d states. In both the ceramics at higher temperatures (above 150 °C) conduction mechanism is taking place via oxygen defect charge carrier hoping. The complex impedance analysis revealed that the distribution of relaxation time of charge carriers is temperature independent. Sm doping in GFO not only changed the dielectric properties but also changed the magnetic coercive field and shape of the magnetic isotherm of GFO.     

Dielectric,ferroelectric, and photoluminescent properties of Sm-doped Bi4Ti3O12 thin films synthesized by sol-gel method

We report on the structure, dielectric, ferroelectric, and photoluminescent properties of Sm³⁺-doped Bi₄Ti₃O₁₂ thin films which were prepared on fused silica and Pt/Ti/SiO₂/Si substrates by sol-gel method. The X-ray diffraction analysis confirmed that the Bi_4-xSm_xTi₃O₁₂ (BSmT) thin films were well crystallized in layered perovskite structure without any secondary phase. Raman spectra indicated that the structure of BSmT thin films was significantly distorted because of the Sm³⁺ doping. An appropriate doping amount of Sm³⁺ ions leads to obvious enhancement in ferroelectric and dielectric properties of BSmT thin films due to structure distortion and reduction in defects. In addition, the BSmT thin films also show orange-red color emission at 601?nm and long florescence lifetime (> 0.6?ms). This study indicated that lead-free BSmT thin films, which are featuring good electrical and photoluminescent properties, may have potential applications in integrated optoelectronic devices.     

Dual effect synergistically triggered Ce:(Y,Tb)3(Al,Mn)5O12 transparent ceramics enabling a high color-rendering index and excellent thermal stability for white LEDs

Ce:Y₃Al₅O₁₂ transparent ceramics (TCs) with appropriate emission light proportion and high thermal stability are significant to construct white light emitting diode devices with excellent chromaticity parameters. In this work, strategies of controlling crystal-field splitting around Ce³⁺ ion and doping orange-red emitting ion, were adopted to fabricate Ce:(Y,Tb)₃(Al,Mn)₅O₁₂ TCs via vacuum sintering technique. Notably, 85.4 % of the room-temperature luminescence intensity of the TC was retained at 150 °C, and the color rendering index was as high as 79.8. Furthermore, a 12 nm red shift and a 16.2 % increase of full width at half maximum were achieved owing to the synergistic effects of Tb³⁺ and Mn²⁺ ions. By combining TCs with a 460 nm blue chip, a warm white light with a low correlated color temperature of 4155 K was acquired. Meanwhile, the action mechanism of Tb³⁺ ion and the energy transfer between Ce³⁺ and Mn²⁺ ions were verified in prepared TCs.     

Structural and magnetic properties of Ce-doped strontium hexaferrite

Ce³⁺ ion substituted Sr-hexaferrite magnetic nanoparticles (MNPs), SrCe_xFe_12-xO₁₉ (0.0?≤?x?≤?0.5) MNPs, were fabricated by citrate sol-gel combustion approach. All products have been characterized using X-ray diffraction (XRD), Photoluminescence, scanning electron microscopy (SEM), elemental mapping (EDS), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) at 300 and 10?K. The XRD pattern presents effective substitution of Ce³⁺ on the sites of strontium hexaferrite lattice. With Ce³⁺ doping, the lattice parameters a is almost unchanged, whereas c is a little increases with increasing the dopant contents. The hysteresis loops M-H showed the ferromagnetic nature of all elaborated. The saturation magnetization (M_s) and the remnant magnetization (M_r) are reduced with increasing Ce amount. All the elaborated products presented typically squarness ratio (M_r/M_s) around 0.5, indicating the existence of non-interacting single domain MNPs with a uniaxial anisotropy. The anisotropy fields (H_a) are found to be very large proving that all products are magnetically hard. With increasing the Ce content, H_a increases which indicate the strengthening of magnetic properties. Consequently, the values of coercive field (H_c) are enhanced, leading these products to be utilized in many uses, such as recording media and permanent magnets. ZFC and FC magnetizations curves indicated shifts of the blocking temperature (T_B) to lower temperatures with increasing Ce content. This is accredited to the reducing of particle size with Ce-substitution.     

Magnetic Properties of Mn‐doped SnO2 Thin Films Prepared by the Sol–Gel Dip Coating Method for Dilute Magnetic Semiconductors

Manganese‐doped tin oxide (SnO₂:Mn) thin films were deposited on glass substrates by the sol–gel dip coating technique. The effect on structural, morphological, magnetic, electrical, and optical properties in the films with different Mn concentrations (0–5 mol%) were investigated. X‐ray diffraction patterns (XRD) showed the deterioration of crystallinity with increase in Mn‐doping concentration. Scanning electron microscopy (SEM) studies showed an inhibition of grain growth with an increase in Mn concentration. X ray photoelectron spectroscopy (XPS) revealed the presence of Sn⁴⁺ and Mn³⁺ in SnO₂: Mn films. SnO₂: Mn films show ferromagnetic and paramagnetic behavior. These SnO₂:Mn films acquire n‐type conductivity for 0–3 mol% (SnO₂ ‐ Sn_0.97Mn_0.03O_{2) ‐}doping concentration and p type for 5 mol% Mn‐doping concentration(Sn_0.95Mn_0.05O₂) in SnO₂ films. An average transmittance of > 75% (in UV‐Vis region) was observed for all the SnO₂:Mn films. Optical band gap energy of SnO₂: Mn films were found to vary in the range 3.55 to 3.71 eV with the increase in Mn‐doping concentration. Photoluminescence (PL) spectra of the films exhibited an increase in the emission intensity with increase in Mn‐doping concentration which may be due to structural defects or luminescent centers, such as nanocrystals and defects in the SnO₂. Such SnO₂:Mn films with structural, magnetic and optical properties can be used as dilute magnetic semiconductors.     

Crystal structure and electrical properties of (Li,Ce, Nd)-multidoped CaBi2Nb2O9 high temperature ceramics

(Li, Ce, and Nd)-multidoped CaBi₂Nb₂O₉ (CBN) Aurivillius phase ceramics were prepared via a conventional solid-state sintering route. The crystal structure including bond lengths and bond angles, microstructure, dielectric constant, DC resistivity, and piezoelectric properties were systematically investigated. Rietveld-refinements of X-ray results indicated that small quantity of (Li, Ce, Nd) doping (< 2.5 mol%) increases orthorhombic distortion, because of the smaller ionic radii of doping ions. However, orthorhombic distortion obviously decreased with increasing (Li, Ce, Nd) doping concentration from 5 to 25 mol%. The replacement of asymmetric A-site Bi³⁺ with 6s2 lone pair electrons by symmetric Li⁺, Ce³⁺ and Nd³⁺ ions decreased the orthorhombic distortion. The morphologies and electrical properties of sintered ceramics were tailored by the introducing (Li, Ce, Nd) multi-dopants. The improvement of piezoelectric properties of modified-CBN ceramics were attributed to decreasing grain sizes and morphotropic phase boundary (MPB). Ca_0.85(Li_0.5Ce_0.25Nd_0.25)_0.15Bi₂Nb₂O₉ (CBNLCN-15) ceramics had optimum properties, and d₃₃ and T_c values were found to be ~ 13.1 pC/N and ~ 900 °C, respectively.