Gd Doping Research Articles

Tailoring hydrogen diffusion pathways in Mg-Ni alloys through Gd addition: A combined experimental and computational study

Magnesium-based alloys represent a promising avenue for solid-state hydrogen storage, yet their practical implementation is impeded by sluggish kinetics and thermodynamic stability. This study presents a systematic investigation into the effects of gadolinium (Gd) and nickel (Ni) content on the microstructure and hydrogen storage properties of Mg-Ni-Gd alloys. Through advanced characterization techniques and density functional theory calculations, we elucidate that Gd preferentially occupies sites in the Mg2Ni phase rather than the Mg matrix, facilitating hydrogen diffusion. The Mg-7.8Ni-2.2Gd alloy demonstrates superior performance, absorbing 5.8 wt% hydrogen at 300 °C, compared to 5.3 wt% for Mg-10Ni under identical conditions. Remarkably, this composition exhibits excellent low-temperature kinetics, absorbing 4.5 wt% hydrogen within 30 min at 120 °C and maintaining 99 % capacity retention after 128 cycles. Post-initial hydrogenation, Gd accumulates at Mg2Ni surfaces, amplifying its role as a “hydrogen pump”. Kinetic analysis using the Chou model for absorption and the Johnson-Mehl-Avrami-Kolmogorov model for desorption provides quantitative insights into the improved hydrogen storage mechanisms. Our computational studies corroborate these experimental findings, revealing that Gd doping in Mg2Ni substantially improves the hydrogen absorption ability, and surface penetration barrier of H atom deeply decreased. This work not only advances our understanding of the complex interplay between composition, microstructure, and hydrogen storage properties in Mg-based alloys but also establishes design principles for high-performance hydrogen storage materials.

Efficient Reduction of Carrier Concentration in SnTe: The Case of Gd Doping

Efficient Reduction of Carrier Concentration in SnTe: The Case of Gd Doping

Influence of Gd doping on mechanical properties, thermal conductivity and microstructural evolution of (Yb1-xGdx)2SiO5 ceramics

Yb2SiO5 is one of the most potential candidate materials for thermal/environmental barrier coating (T/EBC). In order to further reduce its thermal conductivity and improve its mechanical properties, a series of Gd doped Yb2SiO5 [(Yb1-xGdx)2SiO5] ceramics were prepared. The effects of Gd doping on the phase composition, mechanical properties, thermal conductivity and microstructural evolution of Gd doped Yb2SiO5 were investigated. The results showed that (Yb1-xGdx)2SiO5 still maintained a single Yb2SiO5 phase. The average fracture toughness of (Yb1-xGdx)2SiO5 ceramics first decreased and then increased in the investigated Gd-doped Yb2SiO5 samples. (Yb0.9Gd0.1)2SiO5 had the highest fracture toughness (2.56 MPa ·m1/2), which was about 30% higher than that of pure Yb2SiO5. Thermal conductivity of (Yb0.9Gd0.1)2SiO5 ceramic (1.47 W∙m-1∙K-1 at 1200 °C) was about 15% lower than that of pure Yb2SiO5. (Yb1-xGdx)2SiO5 (x≤0.4) had good phase stability after sintering at 1550 °C for 100 h. However, a small amount of Gd9.33(SiO4)6O2 and Yb2Si2O7 two new phases were generated besides Yb2SiO5 phase in the sintered (Yb0.5Gd0.5)2SiO5. Taken together, (Yb0.9Gd0.1)2SiO5 ceramic material will be one of potential candidates for T/EBC.

Synthesis of Ag and Gd Co-doped LaCoO3: Tuning the Optical Bandgap through Quantum Confinement Effect for Outstanding Photocatalytic Activity

Structural defects and tuning in bandgap energy of semiconductors can greatly enhance their catalytic performance as photocatalysts for the removal of various water contaminants. For this purpose, a series of perovskite materials were fabricated. Perovskites have chemical formula A+2B+4(X2-)3, where A site cation is generally an alkaline earth or rare earth metal and B site cation is 3d, 4d, or 5d transition metal. The present study includes the synthesis of LaCoO3, Ag@LaCoO3, Gd@LaCoO3, and Ag/Gd@LaCoO3 by simple co-precipitation route. The prepared materials were characterized using X-ray diffraction and Fourier transform infrared spectroscopy. The average crystallite size and % porosity of Ag/Gd@LaCoO3 were increased to 25 nm and 45% respectively as compared to LaCoO3 (15 nm and 5%) after doping of Ag and Gd in the crystal lattice of pristine LaCoO3. Moreover, the UV-Visible analysis was made to determine the bandgap energy and Urbach energy profiles of fabricated samples. The significant decrease in bandgap energy was noticed for co-doped LaCoO3 i.e. Ag/Gd@LaCoO3 as compared to pure LaCoO3. The calculated bandgap (Eg) values of LaCoO3, Ag@LaCoO3, Gd@LaCoO3, and Ag/Gd@LaCoO3 were 3.11 eV, 2.98 eV, 2.83 eV, and 2.44 eV respectively. The decrement in bandgap energy of Ag/Gd@LaCoO3 could be accredited to the increment in its crystallite size as compared to its other counter parts. The average crystallite size and bandgap energy are in good agreement with each other due to the production of quantum confinement effect in LaCoO3 after doping. Furthermore, the samples were tested for the photocatalytic degradation of bromocresol blue (BCB) and bromocresol green (BCG) under sunlight irradiation of about 60 min. The results of photocatalytic experiments showed 88% and 91% degradation of BCB and BCG respectively by Ag/Gd@LaCoO3 photocatalyst. The enhanced catalytic removal activity of Ag/Gd@LaCoO3 could be assigned to its small bandgap, large crystallite size, high Urbach energy, and high % porosity as compared to pure LaCoO3, Ag@LaCoO3, and Gd@LaCoO3. Hence, Ag/Gd@LaCoO3 can be an efficient photocatalyst for the removal of various industrial effluents.

Effect of Gd doping on the microstructure and electrical characteristics of Maghemite (γ-Fe₂O₃) ceramics

AbstractThis paper presents a novel study on the microstructure and electrical properties of gadolinium (Gd) doped maghemite (γ-Fe₂O₃) nanoparticles, emphasizing their significance for advanced applications in efficient materials. X-ray diffraction analysis confirmed that both pure and doped samples crystallized in a cubic structure (P4332 space group) with high purity. Gd doping significantly increased crystallite size and altered particle morphology, as shown by transmission electron microscopy (TEM), which revealed larger nanoparticles with cubic shapes. Thermal analysis (TGA and DTG) indicated that higher Gd concentrations enhanced thermal instability, affecting structural integrity. FTIR spectra showed shifts in Fe-O bond vibrations, suggesting lattice distortions and increased disorder. BET measurements indicated that higher Gd doping led to greater mesoporosity and surface area, countering expectations of densification. Electrical conductivity and impedance studies revealed two distinct regions: a constant conductivity at low frequencies and an exponential increase at high frequencies, attributed to small polaron hopping. Activation energy values below 200 meV support this mechanism. Gd doping decreased overall conductivity due to disrupted atomic arrangements, increased electron scattering, and modifications in the electronic band structure. Complex impedance spectroscopy illustrated higher real impedance values for doped samples, with increased Gd concentration leading to enhanced impedance. These findings elucidate the impact of Gd on the electrical properties of maghemite nanoparticles and highlight their importance in meeting the growing demands for highly efficient technologies in energy storage and electronic devices. Graphical Abstract

Flash sintering of UO2 pellets for nuclear fuel and wasteform applications

Flash sintering (FS) has been shown to enhance the sintering kinetics in UO2. Using a bespoke AC-FS furnace, high density UO2 pellets, >95 % theoretical density (TD) have been produced followed by scale up and Gd2O3 doping trials. Increasing furnace temperature during FS increases pellet density to a plateau, however, increasing hold time and maximum current both increased the density of UO2 samples to >95 % TD and grain size to ∼4 µm, close to conventional sintering (CS). The optimised FS program reduced sintering temperature and cycle time by ∼50 % compared to CS. Scale up trials showed >96 %TD pellets could be achieved for 11.3 and 14.125 mm diameter green bodies, demonstrating typical fuel pellet diameters are feasible with FS. Gd doping experiments showed with 1 wt% Gd2O3 addition, a ∼92 %TD pellet with ∼2 µm grain size was obtainable, highlighting further optimisation is required for mixed oxide (MOx) materials.

Corrosion and wear mechanisms of rare earth (Gd, Sc, Y)-doped Zr-based amorphous alloys

Rare-earth elements have been utilized in the design and development of new amorphous alloys to improve the corrosion and wear resistance of Zr-based amorphous alloys. In this study, a rare-earth doped Zr-based amorphous alloy (Zr-BMG(RE)) was prepared by the copper mold casting method, which was investigated by corrosion and wear experiments. The results show that Zr-BMG(RE) has a completely amorphous structure, and the doping of rare earths Gd and Y raises the crystallization transition temperature of the amorphous. The addition of rare earth elements Gd and Sc increases the microhardness of Zr-based amorphous alloys, while rare earth element Y causes a slight decrease in microhardness. Gd and Sc will make Zr-based amorphous materials corrosion current density increases, the material pitting and localized corrosion, acid corrosion resistance is reduced. Y doping improves the self-corrosion potential of Zr-based amorphous alloys, reduces the corrosion current density, the surface passivation film is the densest, and the degree of charge transfer on the metal surface is the most difficult, Zr-BMG(Y) has a better corrosion resistance compared with other alloy materials. Zr-BMG(Gd) has the smallest friction rate (1.72 × 10−7mm3N−1mm−1), and the wear rates of the rare earth doped Zr-based amorphous alloys are all smaller than that of Zr-BMG, and the main loss mechanism of Zr-based amorphous alloys is the interaction of adhesive wear, abrasive wear, oxidative wear and fatigue wear. The mechanism of corrosion and wear resistance of rare earth to Zr-based amorphous alloys is discussed, which provides a new idea for the design of amorphous alloys.

Gadolinium doping-induced electronic structure optimization of MIL-101-NH2: Efficient adsorption of arsenic (V) and phosphorus and electrochemical regeneration

The high concentration of acids/bases used to regenerate MOF adsorbents can compromise their structural integrity and may generate additional environmental pollution. The regeneration challenges of MOF adsorbents limit their use in environmental applications. Here, the electronic structure of the iron-based metal–organic framework MIL-101-NH2 was optimized by gadolinium (Gd) doping to provide oxygen vacancies and enhance the electrochemical activity for the selective removal of arsenic(V) and phosphorus from water. 0.75GF-MILN, which was prepared using a gadolinium to iron molar ratio of 0.75, showed a maximum arsenic(V) adsorption capacity of 220.7 mg g−1 and maximum phosphorus adsorption capacity of 112.8 mg P g−1. Increasing the temperature was conducive to the adsorption of arsenic(V) and phosphorus by 0.75GF-MILN, which also maintained a high uptake capacity for arsenic(V) and phosphorus over the pH range of 4.0–9.0. The electro-assisted desorption of arsenic(V) and phosphorus from 0.75GF-MILN was achieved at −3 V. Moreover, 0.75GF-MILN still maintained 99 % arsenic(V) and phosphorus removal efficiencies from real water samples even after four cycles of electro-assisted adsorption–desorption. Density functional theory calculations and electrochemical tests showed that gadolinium doping optimizes the electron structure of MIL-101-NH2, leading to improved electron mobility. This is beneficial for electrochemical elution. Unlike other rare earth-doped MOF materials, arsenic can be desorbed from 0.75GF-MILN using a capacitive deionization process, avoiding the destruction of the MOF via exposure to a highly concentrated acid-base desorption solution. This study provides a design strategy for constructing adsorbents suitable for electrochemical elution to co-remove arsenic(V) and phosphorus, demonstrating the practicality of using rare earth-doped MOF materials in the field of water treatment.

Impact of Gd doping on structural and magnetic characteristics of SrFeO3 perovskite nanomaterial

The SrFeO3nanoparticles doped with 5% and 10% Gd were synthesized using the solution combustion method. The phase formation of the synthesized nanoparticles was confirmed by powder x-ray diffraction analysis. Field emission scanning electron microscope and HRTEM were employed to examine the morphology of the samples, revealing well-ordered, agglomerated nanoparticles. Energy dispersive x-ray spectroscopy analysis was conducted on all samples, confirming the presence of the desired elements. X-ray photoelectron spectroscopy confirmed the presence of mixed oxidation states of Fe3+and Fe4+. Magnetization studies, performed using a SQUID magnetometer, showed ferromagnetic behaviour in all samples, with a significant increase in magnetic moment observed with higher Gd doping. The enhanced magnetic moments and reduced coercivity in Gd-doped SrFeO3suggest that these materials could be suitable for spintronic applications.

Influence on the effect of Gd rare earth doped WO3 nanoparticles for enhanced photocatalytic and antibacterial activities: A nanoplate like morphology

Optimizing the photocatalytic antibacterial properties of nanomaterials by defect engineering is becoming a significant tool. The synthesis and characterization of Gd- doped tungsten oxide (Gd:WO3) nanoparticles for potential applications in wastewater treatment and antibacterial activity. Synthesis of the Gd:WO3 nanoparticles were prepared using the co-precipitation method, known for its simplicity and cost-effectiveness in producing nanomaterials. Samples were characterization by XRD confirmed the monoclinic crystal system of all samples and the incorporation of Gd ions into the WO3 lattice. SEM and TEM revealed a nanoplate-shaped morphology of the synthesized nanostructures. EDS confirmed the composition of Gd:WO3. FT-IR verified the presence of functional groups. XPS investigated the effect of Gd doping on the valence states of Gd:WO3, revealing the location of Gd ions within the WO3 lattice. UV-Vis showed increased absorption in the visible region and a decrease in the band gap with increasing Gd concentration up to 5 wt%, indicating potential photocatalytic properties. The nanoparticles demonstrated significant photocatalytic activity, achieving a 98 % degradation of methylene blue (MB) dye under visible light exposure. Among them, the Gd (5 wt%) nanoparticles exhibited the highest photocatalytic performance within 120 min. Additionally, these Gd (5 wt%) nanoparticles showed the greatest antibacterial effectiveness against Staphylococcus aureus, with an inhibition zone of 20 mm. Moreover, the study demonstrates the potential of Gd-doped tungsten oxide nanoparticles as efficient and environmentally friendly materials for wastewater treatment and antibacterial applications.

Structural, magnetic and electrical properties of gadolinium doped cobalt ferrite nanoparticles: Role of Gd doping level

In this communication, effect of Gd doping for CoFe2–xGdxO4 (CFGO) nanoparticles has been investigated for structural, magnetic and electrical properties. X–ray diffraction (XRD) patterns reveal the presence of matrix like CFGO phase fraction with coexisting GdFeO3 (GFO) smaller crystallites and α–Fe2O3 (FO) phase fraction. Variation in crystallite size (D) for all three phases has been explored from the analysis on XRD patterns. Magnetic nature has been understood on the basis of lattice disorder, magnetic linkages between different ions of CFGO lattices that conduces magnetic characteristic of three different phases coexist within the CFGO nanoparticle lattices. Influence of frequency, temperature and Gd doping level on different electrical behaviors has been understood on the bases of various relaxation processes, charge conduction mechanism, correlated barrier hopping (CBH) mechanism, maximum barrier height, activation energy and structure–property correlations.

NiCr2−xGdxO4 ceramics’ magnetic, structural and electrical conductivity as well as their activation energy properties

The goal of this work is to synthesize and characterize nanoscale nickel chromites nanoparticles doped with Gd using the economical solution combustion method. Numerous analytical techniques, including energy formation, electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction, are used for in-depth characterization. The results show that at low values of coercivity, high values of saturation magnetization, and low values of remnant magnetization, the chromites correspond. The crystalline size of Gd-doped nickel chromites decreases. For the normal spinel structure’s tetrahedral and octahedral coordinated forms, respectively. The present research shows that agglomerated forms and irregular, spherical structures formed by SEM (Scanning Electron Microscope) form regular structures. The present investigation uses a transmission electron microscope (TEM) to illustrate the formation of regular-shaped particles. As demonstrated by Gd-doped NiCr2O4 and pure NiCr2O4, stable interstitial positions are among the typical interstitial positions of the metal oxides. Investigations of magnetic properties from the paramagnetic to the ferromagnetic phase formation. Electrical conductivity and activation energy dropped with Gd doping of nickel chromites and showed an inverse relationship with particle/crystallite sizes. Lastly, applications for NiCr2−x GdxO4 particles were examined and future research directions were also suggested.

Ce(III) formate-derived hierarchical cerium oxide particles with icosahedral symmetry-based architectures: Effect of third level of structural hierarchy in soot and propane oxidation

The article investigates the role of architecture of complex hierarchically structured ceria and gadolinium doped ceria particles in soot combustion (solid-solid reaction) and propane oxidation (gas-solid reaction). Synthesis of hierarchical ceria mesostructures showing icosahedral symmetry-based architecture has been presented for the first time. Carefully choosing synthetic conditions allows to obtain particles with intended morphology of dodecahedron, rhombic hexecontahedron, great stellated dodecahedron, fractal-like branched great stellated dodecahedron and great dodecahemicosacron polyhedra. Twinning-based multiple branching of Ce(III) formate crystals by {101} twin orientation relation was proposed as a driving mechanism for the formation of macroparticles architecture that has been confirmed by the construction of macroparticle models using the identified twinning law. In the catalytic studies, the third level of the material organizational structure referring to shape of hierarchical macroparticles was chosen as a tested variable, while other architecture-related properties were controlled to be alike. In result, the shape of hierarchical particles plays a vital role in the catalytic soot oxidation, and architecture modulation allows the catalytic properties of the material to be enhanced through increasing the geometrical fit between ceria and soot particles. The best sample lowers temperature of half oxidation by 143 °C as compared to non-hierarchically organized ceria nanocrystals. The shape of hierarchical particles does not play leading role in gas-solid propane oxidation, but introduction of Gd dopant diversifies catalytic activity. The architecture of the particles may serve as a modifier of the catalytic activity through grain boundary engineering of gadolinium doped ceria.

The potential of Gd doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

The study shows that the addition of gadolinium ions has a significant impact on the structure, morphology, and adsorption properties of Ni-Co spinel ferrite that was synthesized by the sol-gel auto-combustion method. The research also indicates that the higher the Gd content, the greater the increase in the lattice parameter, which suggests that Gd3+ ions uniformly replaced the octahedral Fe3+ ions. The morphology and chemical composition of Gd-doped Ni-Co ferrites have been studied using SEM and EDS. Gd adding to the NiCoFe matrix increases the BET surface area by 50% (from 48 to 72 m2/g) and promotes the formation of mesopores with an average radius from 3.9 to 4.9nm. The pHPZC values of Gd-doped ferrites are in the range of 7.22-7.39, which means that the ferrite surface will acquire a positive charge at natural pH, so this will promote the adsorption of Congo red anionic dye through electrostatic interaction forces. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to explain the mechanism of CR adsorption on the Ni0.5Co0.5GdxFe2-xO4 adsorbent surface. The ionic-covalent parameter has been estimated to describe the surface acid-base properties. Overall, this study highlights the potential of Gd3+ doping as a promising approach for enhancing the adsorption properties of nickel-cobalt ferrites.

Origin of the ultrahigh field-induced strain in the Gd-doped 0.854Bi0.5Na0.5TiO3-0.12Bi0.5K0.5TiO3-0.026BaTiO3 ternary ceramic system

This study focused on analyzing the ferroelectric, piezoelectric, and dielectric properties of lead-free Bi0.487Na0.427K0.06Ba0.026TiO3 (0.854BNT-0.12BKT-0.026BT) ternary ceramic system by systematically doping 0.001, 0.01, 0.1, 0.5, and 1.0 mol% Gd2O3. The specific composition that was investigated is located at the tetragonal side of the rhombohedral-tetragonal morphotropic phase boundary (MPB) region. Undoped and Gd-doped BNT-BKT-BT ceramics were produced by the conventional solid-state reaction method. Ferroelectric, piezoelectric, and dielectric properties of ceramics were analyzed by carrying out electrical measurements from sintered samples. An ultrahigh field-induced unipolar strain of 0.52% at 65 kV cm−1, with a converse piezoelectric coefficient d33* of up to 795 pm V−1, was achieved with 0.5 mol% Gd doping. This was attributed to the Gd dopant disrupting the normal ferroelectric order and leading to the formation of a nonpolar relaxor phase. The field-induced transition from the nonpolar relaxor phase to the normal ferroelectric phase resulted in relatively large field-induced strain values in the 0.5 mol% Gd-doped ceramics. These results suggest that Gd-doped BNT-BKT-BT ceramics hold promise for digital actuator applications.

Construction of CdS nanosphere with rare earth metal modification over acid theory with boosted photocatalytic hydrogen reaction

Absorption of light, surface reaction and carriers transfer are three main aspects that affect the whole photocatalytic process and activity. Surface modification strategy is widely adopted to promote the light response while still presented poor carriers transfer. Therefore, rare earth metal was introduced to regulate the surface property of the photocatalyst, which shows enhanced photocatalytic performance of 4567.0 μmol h−1 g−1 under optimal rare earth doping compare to 1553.3 μmol h−1 g−1 of pure CdS. The addition of Gd could expose more reactive centers and reduce the recombination of photo-generated carriers. Meanwhile, the doping of Gd could extend the light absorption and accelerate the hydrogen production kinetics.

Gadolinium doping induced the microstructure evolution and mechanical properties improvement of Nb-Si based in-situ superalloy

Nb-Si superalloy is one of the most potential structure-materials of next generation aero engine. The influence of rare-earth element Gd on microstructure and mechanical properties of Nb-16Si-24Ti is explored in this paper. Results show that phase composition no change by doping of Gd. And the mass of Nbss/(Nb, X)3Si eutectic exists in the matrix instead of primary Nbss. The rare-earth element Gd reduces the Si contents in Nbss phases, and the content of O is also limited because of its high active. The deflection, bridging and secondary crack are easily found in coarsened Nbss, and the peak-value of fracture toughness is 8.37 MPa·m1/2 in NST-0.05Gd alloy. The phenomenon of solution strength is obvious, and the maximum value of RT compressive strength is 2214 MPa. The thermal compression test indicates that silicide phases play the major role for high-temperature performance, and the Nbss phases have the poor heat-resistance under HT condition.

Phase engineered enhancement of photocatalytic and Opto-magnetic properties of CuO nanoparticles through fluorine and gadolinium doping

The present study comprises co-doping of CuO nanoparticles with gadolinium (Gd) and fluorine (F) using the sol-gel method to achieve phase stabilization and tune their physicochemical properties. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed successful incorporation of the dopants and the stabilization of the CuO phase with increasing Gd content. Morphological studies revealed grain refinement and an enhanced surface-to-volume ratio upon co-doping. Average particle size decreased from 194 nm to 138 nm for pure and 5%F to 126 nm, 101 nm, and 81 nm for, 1mol%, 2mol% and 3mol% Gd along with 5mol% F co-doped CuO nanoparticles. Increasing the Gd ratio also tuned the band structure and significantly improved the optical properties of the CuO nanoparticles. Additionally, a transition from weak ferromagnetic ordering to paramagnetic behavior is observed. Coercivity decreased to 2.5 Oe for Cu0.97Gd0.03F0.05O0.95 as opposed to 396.3 Oe for CuF0.05O0.95. Photocatalytic activity studies using rhodamine B (Rh B) as a model probe revealed a pronounced enhancement in degradation kinetics with increasing gadolinium (Gd) doping, culminating in around 2.9 times faster degradation rate for 3 % Gd-doped CuO nanoparticles compared to pure CuO nanoparticles. After 3 h of UV light irradiation, the photodegradation efficiency of Cu0.97Gd0.03F0.05O0.95 was 94 %, which is significantly higher than the 80 % and 69 % efficiency of CuF0.05O0.95 and CuO, respectively. These remarkable optical, magnetic, and photocatalytic properties of the co-doped nanoparticles offer promising candidacy for various applications, including photocatalysis, solar energy harvesting, magnetic switching, and magnetic sensing.

Sol-gel auto-combustion synthesis of Co0.5Cu0.5Cr0.5GdxFe1.5-xO4 spinel ferrites and their magneto-dielectric properties

In this work, Gadolinium (Gd3+) substituted Co–Cu–Cr (CCC) SFs with the chemical formula Co0.5Cu0.5Cr0.5GdxFe1.5-xO4 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) were synthesized via the self-combustion process. The single-phase matrix of the Gd3+ substituted CCC SFs was verified using X-ray diffraction (XRD). The crystallite size (D) of Gd3+ doped CCC SFs was reduced from 51.20 nm to 36.27 nm with increasing Gd3+ doping. The addition of Gd3+ in the CCC SFs lattice enhanced specific surface area (S) from 22.11 cm2/g to 28.57 cm2/g. The energy bandgap (Eg) was increased from 4.83 eV to 5.40 eV and revealed an inverse relation with crystallite size. The tangent loss (tan δ), dielectric loss (ε″), dielectric constant (ε′), and ac conductivity (σac) of Gd3+ doped CCC SFs exhibit frequency-dependent behaviour. The behaviour of these dielectric properties has been analyzed using both Koop's theory and the Maxwell-Wagner model. Moreover, it was found that the ε′ was enhanced, while σac and tan δ was reduced with the doping of Gd3+ in CCC SFs. The saturation magnetization and microwave operating frequency were increased with the doping of Gd3+ in CCC SFs. Because of their diverse dielectric and magnetic properties, the Gd3+ doped CCC SFs have considerable potential for different applications, including microwave absorption materials, switching high-frequency devices, and microwave frequency-operating devices.

The influence of Gd3+ion substitution on the microstructure and magnetic properties of NiZnMgGd ferrite

Nowadays, the rapid development and demand of electronic products have prompted electronic components to develop towards miniaturisation and even thin film, high integration and modularisation, high performance and ultra-high frequency applications. With the rapid development of electronic information technology and electronic field, NiZn ferrite material as a representative material in the soft magnetic material, through the optimisation of process technology to develop soft magnetic ferrite material with excellent performance is of great practical significance. In this study, Ni0.3Zn0.5Mg0.2GdxFe1.96-xO4 (x = 0, 0.02, 0.04, 0.06, 0.08) ferrite materials were prepared by an economical solid phase method. The XRD patterns show that NiZnMgGd ferrite materials can be successfully prepared at low doping content of Gd. However, when x ≥ 0.06, the excess Gd3+ reacts with Fe3+ and O2− in the raw material to produce the heterogeneous phase GdFeO3. From the SEM images, it can be seen that the higher the Gd content, the higher the number of small grains in the sample. A small amount of Gd3+ doping has a contributing effect on reducing the Pcv of ferrite. The quality factor of the ferrite sample with x = 0.02 is 11.92 when the frequency is 1000 kHz, which is an improvement of 100.67 % compared to the ferrite without Gd doping. From the M−H curves, Ms decreases with the increasing content of Gd replacing Fe, and NiZnMgGd ferrite is more likely to reach saturation under the action of external magnetic field. Ms, Mr and Hc indicate that NiZnMgGd ferrite material has typical soft magnetic properties.