Effect Of Nd3 Research Articles

Composition dependence of the multifunctional properties of Nd-doped Bi4Ti3O12 ceramics

Sample preparation, evolution of the crystal structure with Nd content at room temperature, as well as dielectric and magnetic properties of polycrystalline Bi4 − xNdxTi3O12 solid solutions (x = 0.0, 0.5, 1.0, 1.5, and 2.0) are reported. These solid solutions were structurally characterized by X-ray powder diffraction using Rietveld refinements. For x ≤ 1.0, the samples crystallize in an orthorhombic symmetry. The structural data could be refined using the polar orthorhombic space group B2cb. The orthorhombicity decreases with increasing Nd3+ concentration, and a paraelectric tetragonal structure (space group I4/mmm) is stabilized for x > 1.The ferroelectric Curie temperature was found to monotonously decrease with increasing Nd concentration. A polar-to-nonpolar phase transition takes place near x = 1, reflecting the existence of a morphotropic phase boundary between 1.0 < x < 1.5 at room temperature. All samples were found to be paramagnetic down to 5 K, however, the presence of significant antiferromagnetic interaction is inferred from Curie–Weiss analyses of the temperature dependence of the magnetic susceptibility of the doped samples. The effect of Nd3+ substitution on structure–property relationship is discussed and compared to that of other lanthanide cations.

Effect of Nd3+ ions on the properties of calcium and strontium barium phosphate glasses

ABSTRACTThis paper reports on the physical, optical and photoluminescence properties of Nd3+ doped calcium barium phosphate (CaO:BaO: P2O5) and strontium barium phosphate (SrO:BaO: P2O5) prepared by the melt-quenching technique at 1200 °C. The density and the molar volume of glass samples were carried out at the room temperature. The results show that the density of glasses tends to increase with increasing concentration of Nd2O3. While, the molar volume of glasses tends to decrease with increasing Nd2O3 contents. The absorption spectra of glass samples centered at 351, 431,463, 473, 514, 526, 581, 628, 683, 747, 804 and 874 nm, respectively were observed in the ultraviolet, visible and near-infrared region. The luminescence spectra of glass samples were investigated in near-infrared region. It was observed that the luminescence spectra of glass samples were dependent on Nd2O3 content. Also, the comparison of calcium and strontium with different of Nd3+ concentration is addressed.

Effect of Nd3+ Concentration on the Spectral-Luminescence of Phosphate Glass

Laser glass was synthesized using a phosphate base with different Nd3+ concentrations, whose composition ensures high glassmaking properties and the possibility of obtaining in small crucibles optically uniform glass. The basic spectral-luminescence characteristics of the obtained glasses are determined and it is shown that this matrix ensures long duration of luminescence and high quantum yield in a wider range of Nd3+ concentrations. Taking account of the good melting and pouring properties this matrix composition is helpful for development work on new laser materials with a modified luminescence band owing to activation by different rare-earth elements and modification of the matrix by highly polarizable cations.

Effects of Nd3+ co-doping on the long lasting phosphorescence and optically stimulated luminescence properties of green emitting NaBaScSi2O7:Eu2+ phosphor

Green emitting NaBaScSi2O7:Eu2+/Eu2+, Nd3+ phosphors are prepared by a solid state reaction under a reductive atmosphere. The introduction of Nd3+ ion, which acts as trap center, largely extends the thermoluminescence characteristics and evidently enhances the long lasting phosphorescence and optically stimulated luminescence properties of the phosphors. The persistent green emission of the co-doped phosphor can last for about five and a half hours above recognizable intensity level (≥0.32mcd/m2). According to the analysis of thermoluminescence characteristics, it is concluded that the shallow T1′ traps with a continuous trap depth distribution are exactly the traps that lead to the long lasting phosphorescence and other three kinds of deep traps, i.e., T2′, T3′ and T4′, corresponding to a separated trap depth distribution, should mainly contribute to the optically stimulated luminescence performance. Finally, a possible mechanism for the optical phenomenon is proposed.

Effect of Nd3+ and Cd2+ ions co-substitution on the dielectric and electron transport properties of spinel strontium nanoferrites

The work reports microemulsion synthesis of spinel nanoferrites having a nominal composition of Sr1−xNdxFe2−yCdyO4 (0.0≤x≤0.1, 0.0≤y≤1.0). X-ray diffraction (XRD) patterns of powdered products annealed at 1073K for three hours revealed the cubic Spinel structure with an average crystallite size in the range of 23–35nm. The room temperature dc resistivity (ρ) has its maximum value for the composition Sr0.92Nd0.08Fe1.2Cd0.8O4. However, for this composition the dielectric parameters and ac conductivity have their minimum values. The magnitudes of these parameters decrease with increasing frequency at low frequency region and then show almost independent frequency behavior at higher frequencies. The results are interpreted in terms of dielectric polarization with great detail. Electrochemical impedance spectroscopy results revealed that conduction process is predominantly governed by grain boundary volume. High resistivity and low dielectric constant of investigated material suggests that it may be employed in microwave devices.

Laser Properties of Nd2O3 Doped Na2O–CaO–SiO2 Transparent Glass-Ceramics for Space Solar Energy

A series of Na2O–CaO–SiO2 glass ceramics containing different content of Nd3+ ions were prepared by the method of high temperature melting and subsequent crystallization. The absorption, excitation and emission spectra of these glass ceramics were investigated; effects of Nd3+ content and crystallization behavior on the laser properties of this material had been studied. The results show that the emission bands originating from the 4F3/2 state of Nd3+ were firstly enhanced with the increase of the Nd2O3 doping content and the crystallinity degree, and then decreased with more doping content and deepened crystallization. The possible reasons of this phenomenon were analyzed. Research will be favored to promote the development of glass ceramics laser materials for space solar energy.

Sol–gel synthesis of Nd-doped BiFeO3 multiferroic and its characterization

Neodymium doped bismuth ferrite (BiFeO3, BFO) nanoparticles were successfully synthesized by a facile sol–gel route. The influence of annealing temperature, time, Bi content and solvent on the crystal structure of BFO was studied. Results indicated that the optimum processing condition of BFO products was 550–600°C/1.5h with excess 3–6% Bi and ethylene glycol as solvent. On the other hand, Nd3+ ion was introduced into the BFO system and the effect of Nd3+ concentration on the structure, magnetic and dielectric properties of BFO were investigated. It was found that the magnetization of BFO was enhanced significantly with Nd3+ substitution, being attributed to the suppression of the spiral cycloidal magnetic structure led by the crystal structure transition. Furthermore, with increasing Nd3+ content, the dielectric constant was found to decrease while the dielectric loss was enhanced, which was mainly due to the hoping conduction mechanism with the reduction of oxygen vacancies.

Effect of Nd3+ on spectroscopic properties of lithium borate glasses

The spectroscopic properties of lithium borate glasses as a function of Nd3+ ions concentration were reported. Optical absorption spectra of these glasses showed a number of absorption bands in ultra violet and visible region. Optical absorption edge was found to shift towards the longer wavelength (red shift) with increase in Nd2O3. Luminescence spectra revealed three major bands at 902, 1063 and 1334 nm which was due to 4F3/2→4I9/2, 11/2 &13/2 transitions of Nd3+ ions. Luminescence intensity was maximum for 1 mol.% Nd2O3 and further increase in Nd2O3 resulted in luminescence quenching. The luminescence quenching behavior at higher concentration of Nd2O3 was attributed to the Nd3+-Nd3+ interaction in the glass matrix. An absorption and emission property of these glasses suggested that these glasses could be useful for 1.06 μm infrared laser applications.

Spectroscopic and electrical studies on Nd3+, Zr4+ ions doped nano-sized BaTiO3 ferroelectrics prepared by sol–gel method

Lead free ferroelectric ceramics in the form of Ba(1−3x)Nd(2x)Ti(1−y)ZryO3 ((where x=0.025, y=0 (BT1), 0.025 (BT2), 0.05 (BT3)) were prepared using sol–gel method. The surface morphology and the orientation of grains of the present ceramics were examined using Field Emission Scanning Electron Microscope (FESEM) images. The effect of Nd3+, Zr4+ ions content on the BaTiO3 was studied using Raman and Fourier Transform Infrared (FTIR) spectroscopies. From the Raman analysis the band observed at ∼838cm−1 was attributed due to the presence of Nd3+-barium vacancy pairs. The FTIR studies suggested that the addition of Nd3+ ions in A-site of BaTiO3 (ABO3) perovskite create lattice distortion by forming A-site vacancies and Zr4+ ions in B-site of BaTiO3 induce the lattice distortion by forming ZrO6 octahedra in the place of TiO6 octahedra. Dielectric measurements of the samples were done at different frequencies from RT-150°C. Charge transportation phenomenon is explained using DC conductivity, which is found to increase with temperature.

Enhanced 2.7 μm emission and its origin in Nd3+/Er3+ codoped SrGdGa3O7 crystal

Nd3+ sensitized Er3+:4I11/2→4I13/2 mid-infrared (MIR) emission around 2.7μm was achieved in SrGdGa3O7 single crystal for the first time. The effect of Nd3+ on the absorption, near-infrared (NIR) and MIR fluorescence properties of Er3+ ions were investigated. It is found that Nd3+ greatly improves the absorption pump efficiency and thus enhances the Er3+~2.7μm emission by nearly 10 times under 808nm laser diode (LD) excitation, at the same time quenches the ~1.5μm near-infrared emission of the lower level Er3+:4I13/2 and thus suppresses the self-saturation problem effectively. The luminescent mechanism for the Nd3+/Er3+:SrGdGa3O7 crystal was analyzed and the possible energy transfer processes were proposed. The energy transfer efficiencies of Nd:4F3/2→Er:4I11/2 and Er:4I13/2→Nd:4I15/2 are estimated to be 85.8% and close to 100%, respectively. The results indicate that the introduction of Nd3+ is very beneficial in achieving 2.7μm laser in Er3+:SrGdGa3O7 crystal which could act as a potential gain media for LD pumped MIR laser.

Enhanced relaxor ferroelectric behavior of BCZT lead-free ceramics prepared by hydrothermal method

Ceramics in the solid solution system, Ba0.9Ca0.1Ti0.9Zr0.1O3–xNd3+, were prepared via a hydrothermal method and were assisted by microwave sintering, and the effects of Nd3+-doping on the electrical properties of Ba0.9Ca0.1Ti0.9Zr0.1O3 were studied. All the samples showed single perovskite structure without a second phase, and a change from the rhombohedral phase to the coexistence of tetragonal and cubic phase occurred at x≥0.025. The dielectric constant and dielectric loss both decreased with increasing Nd3+ content at 0.000≤x≤0.015 and the sample with x=0.020 showed giant permittivity with higher dielectric loss. At x=0.025 and 0.030, the TC significantly decreased and the samples exhibited optimistic relaxor behavior with excellent frequency dispersion. The Pr decreased with increasing Nd3+ content and the samples with x=0.025 and 0.030 showed P–E loops with lower polarization loss. The piezoelectric constant (d33) measured at room temperature increased with increasing Nd3+ addition and exhibited the maximum value at x=0.025. The ferroelectric and piezoelectric properties could not be detected at samples with x=0.020.

The Effect of Nd3+Addition on Crystallization Behavior and Related Properties of the Ferroelectric Glass-Ceramics Na2O-BaO-Nb2O5-SiO2 Based Composition

Ferroelectric glass-ceramics of the Na2O-BaO-Nb2O5-SiO2 system were prepared from parent glass of composition 20Na2O-4BaO-26Nb2O5-50SiO2. Nd2O3 was systematically added in the range 0–3 mol% to the glass compositions as to study its effect on crystallization behavior of the glass and the dielectric properties of the associated glass-ceramics. Heat treatments of the as-quenched samples were performed at the selected temperatures referring to thermal properties that described by the differential thermal analysis. X-ray diffraction studies indicated that NaNbO3 and NaBa2Nb5O15 crystals formed as two main crystalline phases. Involvement of Nd3+ ions in the glass network suppressed precipitation of the NaBa2Nb5O15 phase. The dielectric constant measured at room temperature for glass-ceramic samples were found to sensitive to presence of NaBa2Nb5O15 phase. The present work showed that introduction of Nd3+ into the Na2O-BaO-Nb2O5-SiO2 glass-ceramics system induce slightly change of the dielectric properties.

Effect of Nd3+ substitution on electric field induced strain behavior in lead zirconate stannate titanate (68/22/10) ceramics

Abstract Pb 1−3 x /2 Nd x (Zr 0.68 Sn 0.22 Ti 0.1 )O 3 ceramics with large electrical field induced strain were prepared by Nd 3+ doping. X-ray diffraction analysis showed that the substitution of Nd 3+ for Pb 2+ enhanced the stability of antiferroelectric phase due to the decrease of tolerance factor. Besides, with the increase of Nd 3+ addition, the strain first improved with a maximum value at x = 0.02, and then decreased. Further, with increasing electric field and decreasing measuring frequency, the strain improved obviously. This is because that the reversal of the domains is more sufficient at large electric field and long time. The largest strain of 0.63% is obtained in the specimens with x = 0.02 at the frequency 1 Hz.

Spectroscopic investigation of Nd3 + single doped and Eu3 +/Nd3 + co-doped phosphate glass for solar pumped lasers

We report on the fabrication and characterization of Nd3+ doped phosphate glass to be used as active laser medium for developing solar pumped fiber laser emitting at 1.06μm. Several Nd3+-doped phosphate glass samples were fabricated, with a host composition of (mol%) 65P2O5:17Li2O:3Al2O3:4B2O3:5BaO:6La2O3 and with a concentration of Nd3+ up to 10mol%. In order to exploit the unabsorbed solar energy by Nd3+ ions, Eu3+ co-doping of Nd3+-doped phosphate glasses was also investigated to asses a potential increase in the overall pump power conversion efficiency. Physical and thermal properties of single doped and co-doped samples were measured and their spectroscopic properties are discussed. The effect of Nd3+ doping concentration on emission spectra and lifetimes was investigated in single doped samples in order to study the concentration quenching effect on luminescence performance. The shape of the fluorescence spectrum did not change by increasing the Nd3+ doping level while the lifetime of the Nd3+:4F3/2 was found to decrease. The following characteristic value parameters were calculated: radiative lifetime τ0=367μs and quenching concentration N0=8.47 E+20ions/cm3.The Eu3+ co-doping was found to give a limited increase to the glass pump power absorption limited to the UV range. Although energy transfer from Eu3+ to Nd3+occured, a large Eu3+ concentration dependent quenching of Nd3+ fluorescence was observed. This latter process decreases the radiative quantum efficiency of Nd3+:4F3/2 emitting level and hence limits the attractiveness of Eu3+ sensitization for Nd3+ laser action.

Effect of neodymium substitution on structural and magnetic properties of magnesium ferrite nanoparticles

The effect of Nd3+ substitution on the structural properties of magnesium ferrite prepared by the sol–gel technique was studied in the series MgNdxFe2−xO4, where x = 0–0.3 in steps of 0.05. X-ray diffraction analysis revealed the limit for Nd3+ doping without any secondary phase appearing along with the spinel phase. Particle size calculation shows that the crystallite sizes of the prepared samples are in the 21–30 nm regime. The decrease in value of the lattice parameter with doping suggests that the shrinkage in unit cell and the crystallite size increase with Nd3+ concentration. Fourier transform infrared analysis shows that the substitution of Fe3+ ions is in octahedral B-sites by Nd3+ ions. X-ray fluorescence results show that the composition of prepared samples is in the expected ratio. Transmission electron microscope micrographs revealed spherical morphology and magnetic interaction of the samples. Magnetic measurements revealed the B-site substitution of Nd3+ ions in the series MgNdxFe2−xO4. The variation of magnetic parameters with doping concentration is explained with the help of particle size dependence.

Effect of Nd3+ incorporation on the microstructure and chemical structure of RF sputtered ZnO thin films

The present work aims at investigating the effects that different levels of Nd atoms incorporation can have on the microstructure and chemical structure of ZnO thin films. Undoped and Nd-doped ZnO films were deposited by RF co-sputtering from pure ZnO and metallic Nd targets in Ar plasma onto Si, quartz and glass substrates. The Nd concentration in the ZnO host matrix was varied in the range 0–26 at.% by varying the bias applied to the Nd target. A comprehensive characterization of the films properties was performed by X-ray photoelectron and Auger electron spectroscopies, X-ray fluorescence analysis, X-ray diffraction and scanning electron microscopy. At low Nd atomic concentration (Nd/Zn < 0.07) Nd atoms were successfully incorporated into the ZnO matrix, whose crystalline structure was preserved. A deterioration of the ZnO würtzite phase was observed on the contrary with increasing Nd content in the films together with the precipitation of a second phase, identified as Nd2O3.

Structural, optical, and electrical properties of Nd-doped Na0.5Bi0.5TiO3

The effects of Nd3+ addition on structure and functional properties of Na0.5Bi0.5TiO3 (NBT) are examined. X-ray crystallography has allowed the identification of a continuous solid solution with the general formula Na0.5[Bi1−xNdx]0.5TiO3. In the composition range 0≤x≤0.25 the structure was found to crystallize in rhombohedral symmetry while for higher Nd3+ concentrations tetragonal symmetry is favored. The functional properties are investigated in more detail for the solid solution containing 5% Nd3+ where an overall improvement of the ferroelectric properties and a rather high pyroelectric coefficient could be obtained. The fluorescence behavior of this composition is also reported. It is thought that Nd3+ doped NBT may be highly promising for a range of applications requiring lead-free ferroelectrics with improved properties.

Effects of Nd3+ concentration on properties of yttrium lanthanum oxide transparent ceramics

The effects of Nd3+ concentration on the visible fluorescence spectroscopic properties of Nd:(Y0.9La0.1)2O3 transparent ceramics are investigated. Under 270 nm excitation, three emission peaks are observed at 396, 426, and 633 nm. When the Nd3+ concentration is increased, intensities of the peaks at 396 and 426 nm increase while the 633 nm peak become weak due to the fluorescence re-absorption effect. Broad luminescence band centered at 426 nm is observed from the fluorescence spectrum stimulated at 358 nm. The emission intensity increases with the increase of Nd3+ ion content firstly, then decreases owing to the concentration quenching of Nd3+ ions.

Properties of neodymium-doped Ca0.15Sr1.85Bi4Ti5O18 ferroelectric ceramics

Bismuth-layered compound Ca0.15Sr1.85Bi4−xNdxTi5O18 (CSBNT, x = 0–0.25) ferroelectric ceramics samples were prepared by solid-state reaction method. The effects of Nd3+ doping on their ferroelectric and dielectric properties were investigated. The remnant polarization Pr of CSBNT ceramics increases at beginning then decreases with increasing of Nd3+ doping level, and a maximum Pr value of 9.6 μC/cm2 at x = 0.05 was detected with a coercive field Ec = 80.2 kV/cm. Nd3+ dopant not only decreases the Curie temperature linearly, but also the dielectric constant (er) and dielectric loss tangent (tan δ). The magnitudes of er and tan δ at the frequency of 100 kHz are estimated to be 164 and 0.0083 at room temperature, respectively.

Thermo-optical characteristics and concentration quenching effects in Nd3+doped yttrium calcium borate glasses

In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd(2)O(3)-(5-x)Y(2)O(3-)40CaO-55B(2)O(3) (0 ≤ x ≤ 1.0 mol%). Their fluorescence quantum efficiency (η) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Förster-Dexter model of multipolar ion-ion interactions. A maximum η = 0.54 was found to be substantially higher than for yttrium aluminoborate crystals and glasses with comparable Nd(3+) content. As for the thermo-optical properties of yttrium calcium borate, they are comparable to other well-known laser glasses. The obtained energy transfer microparameters and the weak dependence of η on the Nd(3+) concentration with a high optimum Nd(3+) concentration put this system as a strong candidate for photonics applications.