Y2O3 Doping Research Articles

Influence of the Y3Al5O12 on the structure formation and properties of ceramics of the Al2O3 – Y2O3 system

The paper presents results of the study of the structure and physico-mechanical properties of ceramics composits α-Al2O3 + n Y2O3 (n = 0; 0.5; 1; 1.5; 2; 3; 4; 5 wt.%) based on the basis of polymorphic modifications γ+θ-Al2O3 depending on the concentration of the Y2O3 doping impurity and the annealing temperature of the powder mixtures (800 and 900°C). The effect of mutual protection against crystallization was discovered, which results in mutual inhibition of crystallization processes in Al2O3–Y2O3 powder systems. By X-ray diffraction analysis, the formation of a phase of yttrium-aluminum garnet Y3Al5O12 (YAG) in ceramics has been established. The dependence of the mechanical characteristics of the materials under study on the amount and size of the formed phase YAG has been revealed.

Influence of Y2O3 doping on the aging behavior and mechanical properties of ATZ ceramics

The aim of this study was to investigate the influence of the Y2O3 content on the mechanical properties and aging behavior of ATZ ceramic. For this purpose, an ATZ ceramic consisting of 80 wt% stabilized ZrO2 and 20 wt% Al2O3 with varying Y2O3 stabilizer content between 2 and 3 mol% was prepared. The samples were analyzed regarding their sintered density, grain size, hardness and fracture toughness. The results show an increase in fracture toughness and a decrease in hardness with decreasing Y2O3 content. In addition, the aging stability was assessed by analyzing the phase composition determined by X-ray diffraction after aging the samples for up to 150 hours in steam atmosphere at 134 °C and 2 bar. The aging stability decreases with decreasing stabilizer content. Nevertheless, by producing a very fine-grained material, high aging stability can be achieved despite reduced Y2O3 content.

Influence of Y2O3 Doping on Phase Evolution and Dielectric Characteristics of ZrO2 Ceramics.

Improvements in phase stability and dielectric characteristics can broaden the applications of zirconia in ceramics. Herein, a series of Y2O3-stabilized zirconia (YSZ) ceramics are synthesized using solid-state sintering, followed by an investigation into their phase evolution, grain size, dielectric constant, and breaking field. As the Y2O3 content increases from 0 wt% to 4 wt%, the as-grown YSZ ceramics undergo a distinct phase transformation, transitioning from monoclinic to monoclinic + tetragonal and further to monoclinic + tetragonal + cubic, before finally returning to monoclinic + cubic. Significant changes occur in the internal microstructure and grain size of the ceramics as the phase composition alters, resulting in a reduction in grain size from 3.17 μm to 0.27 μm. Moreover, their dielectric constants exhibit an increasing trend as the Y2O3 content increases, rising from 3.92 to 13.2. Importantly, the dielectric breakdown field of these YSZ ceramics shows a similar variation to the phase evolution, ranging from 0.11 to 0.15 MV/cm. This study sheds light on the phase evolution and dielectric properties of YSZ ceramics, offering an efficient strategy for enhancing their dielectric performances.

Enhanced mechanical properties of TZM alloy via doping Y2O3 along with creating heterogeneous grain structures

The further application exploration of TZM alloys have been hindered by the limited strength especially at high temperatures. Herein, we propose a strategy to enhance the mechanical properties of TZM alloys by introducing heterostructures through Y2O3 doping combined with rotary forging (RF). The particle stimulated nucleation (PSN) mechanism promotes fine grains (FGs) nucleate close to the micron-sized second phase particles. The mechanical properties of Y2O3-TZM (YTZM) alloy are improved through the synergistic strengthening influence of back stress strengthening and second phase strengthening. The ultimate tensile strength (UTS) of YTZM at room temperature and 1000 °C is 820 MPa and 433 MPa, respectively, which are about 15% and 51% higher than that of TZM. In addition, the FCC-oxides generated by adding Y2O3 can trigger twinning, stacking faults, and 9R structures during high-temperature deformation, and the long-period stacked ordered phase (LPSO) nucleates at the stacking faults and twin boundaries through the 9R structures, which is more conducive to alleviate the stress concentration at the oxide/matrix interface and improve the dislocation blocking ability. The present strategy provides a paradigm for the development of high-performance TZM alloys through creating heterostructures.

Hydrogen generation by hydrolysis of alkaline NaBH4 solution doped with amorphous catalyst Co–Y2O3–B/CNTs

This investigation enhances the catalytic efficiency of Co–B/CNTs for hydrogen production via sodium borohydride hydrolysis by doping with 5%Y2O3. Such doping significantly boosts hydrogen evolution rates, with Co–Y2O3–B/CNTs achieving a production rate of 1083.43 ml g−1·min−1—surpassing Co–B/CNTs by 1.5 times and tripling that of Co–B catalysts. SEM and XRD analyses show Y2O3 doping reduces particle aggregation and maintains the catalyst's amorphous state, thereby increasing the active surface area. Furthermore, XPS analysis demonstrates that introducing yttrium into Co–B/CNTs catalysts improves their surface elemental composition and valence states. This improvement boosts catalyst performance and stability by enhancing electron transfer and particle size optimization. Optimal hydrolysis is achieved at an NaOH concentration of 2.5 mol/L, with higher concentrations diminishing hydrogen production due to increased viscosity from by-product formation. Additionally, Co–Y2O3–B/CNTs catalysts exhibit commendable durability, maintaining more than two-thirds of their initial activity after five reuse cycles, outperforming comparable catalysts to a moderate extent. These findings underscore the beneficial role of Y2O3 in the Co–B/CNTs framework, promoting Y2O3-doped catalysts for their enhanced efficiency, sustainability, and hydrogen production capabilities.

Effect of Y2O3 doping on thermophysical properties and grain growth rate of lanthanum zirconate

Notwithstanding the impressive phase stability and low thermal conductivity exhibited by lanthanum zirconate (LZ), its low coefficient of thermal expansion is deemed a paramount limitation. In the present study, (La1-xYx)2Zr2O7 with x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, as new TBCs, were synthesized by reverse co-precipitation and calcination method. The XRD and Raman analyses elucidated that the substitution of Y3+ ions occurred exclusively at the La3+ positions. In addition, in accordance with FESEM and DTA findings, the incorporation of Y2O3 has induced a reduction in particle size and an enhancement in crystallization resistance. The evaluation of the coefficient of thermal expansion (CTE) demonstrated a notable improvement following the introduction of Y2O3. Specifically, the CTE of LZ increased from 9.34 × 10−6 °C-1 to 10.5 × 10−6 °C-1 in the case of (La0.5Y0.5)2Zr2O7 at 1100oC. Investigations of phase stability following a 50 h heat treatment at 1300oC indicated that Y2O3 had no impact on phase stability. All compounds, similar to LZ, exhibited excellent phase stability. Furthermore, the addition of Y2O3 significantly amplified the grain boundary diffusion mechanism during heat treatment, leading to an accelerated grain growth rate. The grain growth rate increased from 1.7 nm/h at LZ to 2.2 nm/h in the case of (La0.6Y0.4)2Zr2O7.

Effect of Y2O3 doping content on phase composition, mechanical properties and cavitation erosion performance of ZrO2 ceramics

Y2O3 stabilized ZrO2 (YSZ) is considered to be promising in resisting force-heat coupling damage caused by cavitation erosion (CE). However, the impact of doping Y2O3 on the microstructure and properties of ZrO2 is extremely complex, and there is still a lack of understanding about it, let alone the mechanism of these factors on the CE performance. In light of this, the present study investigated the effects of Y2O3 doping content (3 mol%, 7 mol% and 17 mol%) on the phase composition, grain size, microstructure, density, mechanical properties and CE performance of YSZ, and deeply analyzed the CE mechanism. The results indicated that the Y3+ entering the zirconia lattice effectively stabilized the high-temperature phases (t, t′ and c) and suppressed the formation of m-phase. With the increase of Y3+ concentration, the content of t continuously decreased while that of c continuously increased, so that only t + t′ phases were contained in the 3YSZ and only t′+c phases were contained in the 17YSZ. Meanwhile, the grain sizes and pores were constantly increasing, which obviously deteriorated the hardness, toughness and CE resistance. The t→m transformation under the action of cavitation load effectively absorbed impact energy and suppressed the propagation of fatigue cracks, thereby significantly delaying the fatigue spallation of materials. The 3YSZ with the densest microstructure, the best mechanical properties, the smallest grain size and the highest content of t-phase exhibited the best CE resistance. However, the continuous accumulation of m-phase at the grain edge, especially the amorphous structure formed by hydrolysis promoted by cavitation heat, provided a preferential channel for the propagation of fatigue cracks, and thus ultimately led to the exfoliation of the grains.

Effects of CeO2/Y2O3 rare earth oxides on microstructure and properties of in-situ synthesized WC-reinforced Ni-based cladding layer

A novel tungsten carbide (WC)-reinforced nickel (Ni)-based laser cladding layer was prepared through an in-situ synthesis process. The influence of different concentrations of CeO2/Y2O3 on the microstructure, wear, and corrosion resistance of the in-situ synthesized WC-reinforced Ni-based cladding layer was analyzed. The results revealed that the coatings doped with rare-earth oxides exhibited good micro-hardness (660 HV0.2) and wear resistance when the rare-earth oxide content reached 0.75% CeO2 and 1.50% Y2O3. Additionally, the minimum corrosion rates of the coating were measured at 0.002770 mm/a and 0.0022548 mm/a at 1.5% CeO2 and 1.5 Y2O3 doping, with noble Ecorr values ranging from -0.12549 V to -0.49924 V and lower Icorr values ranging from 2.3550?10-7 A?cm2 to 1.9170?10-7 A?cm2. Furthermore, the wear resistance of the cladding layer was significantly higher than that of the substrate. Both the cladding layer and the substrate exhibited a mixed-wear mode, and they exhibit adhesive wear in wet friction environments.

Study on Structural Stability of ZrO2 and YSZ: Doping-Induced Phase Transitions and Fermi Level Shift

This work summarizes the results of structural stability, electronic properties and phonon dispersion studies of biocompatible ZrO2 compound in its cubic (c-ZrO2), tetragonal (t-ZrO2) and monoclinic (m-ZrO2) phases. The authors found that the monoclinic phase of zirconium dioxide is the most stable among the three phases in terms of total energy, lowest enthalpy, highest entropy, and other thermodynamic properties. The presence of rather weak frequencies for m-ZrO2 also confirms the monoclinic phase as a stable conformation of zirconia. Our analysis of the electronic properties showed that during the m-t phase transformation of ZrO2, the Fermi level first shifts by 0.125 eV toward higher energies and then decreases by 0.08 eV in the t-c cross-section. The band gaps for c-ZrO2, t-ZrO2, and m-ZrO2 are 5.140 eV, 5.898 eV, and 5.288 eV, respectively. Calculations to study the effect of 3.23, 6.67, 10.35 and 16.15 mol%Y2O3 on the structure and properties of m-ZrO2 showed that the enthalpy of m-YSZ decreases linearly and accompanies further stabilization of zirconium dioxide. Doping-induced phase transitions of ZrO2 were discovered under the influence of Y2O3 doping, due to which the position of the Fermi level changes and the band gap decreases. It has been established that, not only for pure systems but including those doped with Y2O3, the main contribution to the formation of the conduction band is made by the p-states of electrons.

Improvement of electrical performance of ZnO linear resistors by Y2O3 doping

ZnO-TiO2−MgO-Al2O3 linear resistors with various Y2O3 dopant concentrations were fabricated using the conventional solid-state reaction method. The comprehensive investigation of the impact of Y2O3 addition on the microstructure and electrical characteristics of the resistors was carried out. The results indicated that the Y2O3 phase hindered the growth of zinc oxide particles. Additionally, the incorporation of yttrium oxide increased the linearity of the resistors and affected the height of the grain boundary barrier (φb). Subsequently, a Y2O3-doped ZnO linear resistor with a nonlinearity constant (α) of 1.09 and a resistance-temperature constant (αT) of -2.51 × 10−3/ °C was effectively produced. The comprehensive evaluation of the microstructure and relevant electrical characteristics enables the efficient production of linear resistors with excellent electrical properties.

Interface Bonding Properties of CrAlSiN-Coated Cemented Carbides Doped with CeO2 and Y2O3 Rare Earth Oxides.

This study performed first-principle-based calculations of the interface adhesion work in interface models of three terminal systems: CrAlSiNSi/WC-Co, CrAlSiNN/WC-Co, and CrAlSiNAl/WC-Co. The results proved that the CrAlSiNSi/WC-Co and CrAlSiNAl/WC-Co interface models had the highest and lowest interface adhesion work values (4.312 and 2.536 J·m-2), respectively. Thus, the latter model had the weakest interface bonding property. On this basis, rare earth oxides CeO2 and Y2O3 were doped into the Al terminal model (CrAlSiNAl/WC-Co). Then, doping models of CeO2 and Y2O3 doped on the WC/WC, WC/Co, and CrAlSiNAl/WC-Co interfaces were established. The adhesion work value was calculated for the interfaces in each doping model. When CeO2 and Y2O3 were doped in the WC/WC and CrAlSiNAl/WC-Co interfaces, four doping models were constructed, each model contains interfaces withreduced adhesion work values, indicating deteriorated interface bonding properties. When the WC/Co interface was doped with CeO2 and Y2O3, the interface adhesion work values of the two doping models are both increased, and Y2O3 doping improved the bonding properties of the Al terminal model (CrAlSiNAl/WC-Co) more significantly than CeO2 doping. Next, the charge density difference and the average Mulliken bond population were estimated. The WC/WC and CrAlSiNAl/WC-Co interfaces doped with CeO2 or Y2O3, with decreased adhesion work, exhibited low electron cloud superposition and reduced values of charge transfer, average bond population, and interatomic interaction. When the WC/Co interface was doped with CeO2 or Y2O3, superposition of the atomic charge densities of electron clouds was consistently observed at the CrAlSiNAl/WC-Co interface in the CrAlSiNAl/WC/CeO2/Co and CrAlSiNAl/WC/Y2O3/Co models; the atomic interactions were strong, and the interface bonding strength increased. When the WC/Co interface was doped with Y2O3, the superposition of atomic charge densities and the atomic interactions were stronger than for CeO2 doping. In addition, the average Mulliken bond population and the atomic stability were also higher, and the doping effect was better.

The benefit of Ca in improving pinning of BaZrO3-Y2O3 doubly-doped YBa2Cu3O7-x/Ca0.3Y0.7Ba2Cu3O7-x multilayer nanocomposite films

This work examines the pinning enhancement in BaZrO 3 (BZO) +Y2O3 doubly-doped (DD) YBa2Cu3O7 (YBCO) nanocomposite multilayer (DD-ML) films. The film consists of two 10 nm thin Ca0.3Y0.7Ba2Cu3O7-x (CaY-123) spacers stacking alternatively with three BZO + Y2O3/YBCO layers of 50 nm each in thickness that contain 3 vol% of Y2O3 and BZO doping in the range of 2–6 vol%. Enhanced magnetic vortex pinning and improved pinning isotropy with respect to the orientation of magnetic field (B) have been achieved in the DD-ML samples at lower BZO doping as compared to that in the single-layer counterparts (DD-SL) without the CaY-123 spacers. For example, the pinning force density (F p ) of ∼58 GNm−3 in 2 vol.% of DD-ML film is ∼110% higher than in 2 vol% of DD-SL at 65 K and B//c-axis, which is attributed to the improved pinning efficiency by c-axis aligned BZO nanorods through diffusion of Calcium (Ca) along the tensile-strained channels at BZO nanorods/YBCO interface for improvement of the interface microstructure and hence pinning efficiency of BZO nanorods. An additional benefit is in the considerably improved J c (θ) and reduced J c anisotropy in the former over the entire range of the B orientations. However, at higher BZO doping, the BZO nanorods become segmented and misoriented, which may change the Ca diffusion pathways and reduce the benefit of Ca in improving the pinning efficiency of BZO nanorods.

Thermophysical and mechanical properties of cubic, tetragonal and monoclinic ZrO2

Yttrium-stabilized zirconia (YSZ) materials are routinely used as thermal barrier coatings (TBCs). The phase composition and microstructure of YSZ materials significantly influence their properties. In this study, ZrO2 ceramics composed respectively of monoclinic ZrO2 (m-ZrO2), tetragonal YSZ (t-YSZ) and cubic YSZ (c-YSZ) phases were sintered. The effect mechanism of phase composition and microstructure on thermophysical and mechanical properties were investigated by experiment together and numerical calculation. The result indicates that YSZ materials with c-YSZ phase are more suitable as TBC materials in terms of heat insulation, thermal expansion match with the metal substrate, and strain tolerance. The YSZ ceramic with c-YSZ phase also exhibits lower thermal conductivity than those composed of the t-YSZ and m-ZrO2 phases due to its greater lattice distortion, number of oxygen vacancies, and lower sound velocity as a result of greater Y2O3 doping. Bond lengths and cohesive energy calculations based on first principles reveal that the reason that the Y2O3 doping causes the CTE values of ZrO2 to increase is due to the bonding between ions becoming weaker, and the c-YSZ phase exhibits the highest CTE value. First-principles calculations also indicate that the c-YSZ phase exhibits a lower elastic modulus and better malleability and plasticity than m-ZrO2 and t-YSZ phases. However, the t-YSZ phase has better fracture toughness due to toughening under stress and finer grains.

Effect of Y2O3 content on densification, microstructure and mechanical properties of reaction sintered magnesium aluminate spinel

Dense magnesium aluminate (MgAl2O4) spinels were developed via single-stage solid-state reaction sintering method at 1550–1650oC using combinations of varied commercial grade reactants-three different sources of alumina and two different sources of magnesia. The effect of Y2O3 doping in the concentration range of 1–4 wt % on different spinel batches was studied. Y2O3 addition was found to favour the densification of all the spinels at all dopant concentrations and maximum densification was found for the 2 wt % Y2O3 containing spinel batches. Phase analysis of the Y2O3 containing batches revealed the presence of yttrium aluminum garnet (YAG, Y3Al5O12) at all the sintering temperatures. Owing to similar crystal structure isotropic configuration of YAG (cubic) as that of spinel (cubic), Y2O3 doping was found to favour densification of spinel. Microstructural investigation revealed that Y2O3 containing batches have a controlled grain structure as compared to the without additive batches. Also, 2 wt % Y2O3 containing spinel batches sintered at 1650oC revealed better mechanical properties such as cold modulus of rupture and strength retainment after thermal shock than that of the undoped spinel batches.

Effects of Y2O3 doping on the phase composition, chemical diffusion coefficient and electrochemical properties of CaHfO3 proton conductor

In order to further understand the effect of Y2O3 doping on the electrical conductivity of CaHf1−xYxO3−δ, which was prepared by conventional solid-state reaction. The electrical conductivity of CaHf1−xYxO3−δ was measured by two-terminal AC method in an oxygen-rich atmosphere, hydrogen-rich atmosphere and water vapor-rich atmosphere at the temperature between 973 and 1373 K. The test results show that the conductivity of CaHf1−xYxO3−δ first increases and then decreases with x from 0.08 to 0.20, and its total conductivity and conductivity activation energy are 3.88 × 10−7 to 5.34 × 10−5S/m and 0.76–0.92eV respectively. Combined with the test results of the H/D isotope effect, it is found that protons are the main conductive carriers in the three different atmosphere at temperatures range of 973–1173 K. In addition, in the temperatures range of 1273–1373 K, the positive holes are the main conductive carriers in the oxygen rich atmosphere, and the vacancies participates in the conductive process as the main conductive carriers in the water vapor rich atmosphere. The chemical diffusion coefficients of CaHf1−xYxO3−δ is 3.9 × 10−6 to 2.4 × 10−5 cm2/s in the temperature range of 973–1373 K. According to the test results of electromotive force, the theoretical electromotive force is consistent with the measured electromotive force. The proton transfer number of CaHf1−xYxO3−δ exceeded 97% in hydrogen atmosphere at temperatures from 973 to 1173 K. In sum, these findings of CaHf1−xYxO3−δ can be used as alternative materials for hydrogen sensor electrolytes.

Recycling of optical borosilicate waste glasses by Y2O3 doping for radiation shielding applications

In the present study, borosilicate glass-ceramics doped with Y2O3 were prepared and characterised for their structure and shielding prowess. Borosilicate waste glasses doped with Yttrium as a rare earth element from Y2O3 were prepared through the cold isostatic press method. The glass-ceramics had the chemical formula 81SiO2-12B2O3–4Na2O-3Al2O3-XY2O3, where X = 0, 10, 20% by weight. The structure of the prepared glasses was studied by the X-ray diffraction method while the density and hardness of the sample were measured experimentally. The ability of the glasses to absorb gamma-ray photons, moderate fast neutrons, and thermal neutrons was estimated from Monte Carlo simulations and established theoretical calculations. Samples containing 0% and 10% weight fraction exhibited mainly glassy structures, while the XRD spectrum of the sample containing 20% Y2O3 by weight displayed a glass-ceramics structure. The Vickers hardness values were calculated as 453, 501 and 551 HV under a 0.5 kg load for Y2O3 content of 0, 10, and 20 wt%. The density of the pristine borosilicate glass was 2.03 gcm−3. The addition of 10% and 20% by weight of Y2O3 increased the density by 9.85% and 18.07%, respectively. The mass attenuation coefficient values show strong energy fluctuations from 0.02046 to 5.18560 cm2/g for BS1, 0.02179–6.49902 cm2/g for BSY1, and 0.02313–7.81340 cm2/g as E decreases from 15 MeV to 15 keV. In addition, increasing the Y2O3 weight proportion in the samples increases photon buildup. The introduction of Y2O3 into the pristine borosilicate glass was found to increase the removal and total cross-sections for fast and moderated neutrons, respectively. The glass-ceramics demonstrated attributes useful for radiation absorption applications.

Effect of Y2O3 on the structural, optical and radiation shielding properties of transparent Na-rich borate glass with diluted and fixed Fe2O3

We study the impact of yttrium oxide (Y2O3) on the optical properties of iron-doped borate glasses. A series of borate glasses, with a diluted and constant amount of Fe2O3, doped with various amounts of Y2O3 (labeled as BNaFeY-glasses) was prepared and studied. The impact of Y2O3 doping on the optical transitions of BNaFeY-glasses was studied by analyzing the optical absorption spectra. The presence of Fe cations, with their Fe3+ state, leads to the appearance of absorption in the ultraviolet region. Furthermore, the optical transmittance spectra proved the transparency of all BNaFeY-glasses. Moreover, the transmittance of the sample with the highest Y2O3 content is about 93 % within the visible range. Because of the diluted Fe content within BNaFeY-glasses, the five absorption bands of Fe are not observed. So, these bands are detected by magnifying the spectra within the visible region. These bands are labeled ʋ1, ʋ2, ʋ3, ʋ4 and ʋ5 at wavelengths 454.5, 518.4, 652.5, 707 and 808 nm respectively. These bands were used to calculate the crystal field splitting (10Dq) for all BNaFeY-glasses. The outstanding 10Dq increment with further Y2O3 doping was explained in terms of more interactions between Fe cations and their surroundings. On the other side, the shielding parameters were considered to examine the competence of these transparent glasses against nuclear radiation. We found that the sample doped with the highest amount of Y2O3 has the highest linear attenuation coefficient and the lowest half-value layer (HVL). From the HVL results, we need a thickness of 3.646 cm from the sample with 5 mol% of Y2O3 to get protection from 50% of the photons with energy of 0.662 MeV, and this thickness is increased to 5.137 cm when the energy is 1.333 MeV.

Effect of Y2O3/La2O3 on structure and mechanical properties of Li2O–Al2O3–SiO2 glass

Effect of Y2O3 and La2O3 substitution for SiO2 on the structure and mechanical properties of Li2O-Al2O3-SiO2 (LAS) glass was investigated. The structural changes were characterized by 27Al magic angle spinning nuclear magnetic resonance (MAS-NMR), Fourier transform infrared spectrometer (FTIR) and viscosity-temperature tests. The results showed that LAS glass network structures depolymerized firstly and then polymerized with increasing Y2O3 or La2O3 content. Atomic packing density of LAS glasses monotonically increased as the addition of Y2O3 or La2O3 and its best measurement value is 0.5824 with the Y2O3 and La2O3 doping content are 4 mol% and 2 mol% (denoted as LAS-42). Simultaneously, Vickers hardness, elastic modulus and bending strength were measured and their best values corresponded to 712.80 HV, 99.72 GPa and 140.47 MPa when the glass is LAS-42, with the increases of 13.1%, 14.9% and 59.9%, respectively. This study revealed that high dissociation energy oxides, in terms of Y2O3 and La2O3, have obvious effects on improving mechanical properties of LAS glass.

Effects of calcination temperature on grain growth and phase transformation of nano-zirconia with different crystal forms prepared by hydrothermal method

The nano-Zirconia powders doped with different yttrium content (YSZ) were prepared by hydrothermal method, and then calcined in the atmosphere. The grain growth kinetics and mechanism of YSZ powder were analyzed. The addition of Y2O3 can refine the zirconia grains, and the mechanism of its action is discussed, and the grain sizes of the hydrothermal nano-powders (0, 3 and 11 YSZ) prepared with different Y2O3 are 15.4, 13.7 and 8.0 nm, respectively. The phase transformation mechanism of 3 YSZ powder and the influence mechanism of Y2O3 doping in different stages on powder growth are discussed. The growth mechanism of powder in different stages is analyzed and expounded. The first stage grain growth mechanism of 3 YSZ and 11 YSZ powders is dominated by surface diffusion and grain boundary rotational polymerization growth mechanisms, while the second stage grain growth is dominated by lattice diffusion and grain boundary migration polymerization growth mechanisms.

Impact of Y2O3 on the structural, optical, radiation shielding, and ligand field parameters of transparent borate glass containing constant CrO3 and high Na2O contents

This study aims to investigate the impact of the rare earth element yttrium on the optical properties of chromium (Cr)-doped borate glasses. A series of borate glasses (labeled as BNaCrY glasses) were prepared and studied, each with a constant amount of chromium trioxide (CrO3) but doped with varying amounts of yttrium oxide (Y2O3). Infrared analysis revealed four distinct spectral areas in the internal structure of all BNaCrY glasses. Optical absorption spectra were used to investigate the impact of Y2O3 doping on the optical transitions of BNaCrY glasses. The presence of Cr cations caused the appearance of an absorption band at 379–383 nm, which overlapped with the Urbach edge that is commonly given an edge-like at 430 nm. The Urbach edge has been manifested through a full deconvolution attempt. Cr cations in the Cr3+ state were confirmed by visible absorption bands and are nestled in the octahedral positions. The band at 574–593 nm was used to determine the crystal field splitting (10Dq) for all BNaCrY glasses. Due to the increased number of O anions around the Cr cation, the values of 10Dq increased with Y2O3 doping. The remarkable increase in 10Dq was attributed to increased interaction between Cr cations and their surroundings. In contrast, the shielding parameters were taken into account when evaluating the ability of these transparent glasses to protect against nuclear radiation. We found that the sample with the highest Y2O3 concentration had the highest linear attenuation coefficient and the lowest half-value layer. Thus, BNaCrY glasses are more efficient as attenuators than commercial glasses (such as the Rider and Osmania glasses), especially at low photon energies.