Ce Ions Research Articles

Evidence for nanosized magnetic clusters of Ce-ions in the archetypal heavy fermion metal CeB6

Fine details of crystal structure of archetypal CeB6 hexaboride with heavy fermions are studied at temperatures 85 and 500 K by precise X-ray diffraction technique. Small static Jahn-Teller distortions of a simple cubic lattice are observed at these temperatures, leading to emergence of (i) dynamic charge stripes along selected directions <110>, <100>, and <111> in the crystals in combination with (ii) vibrationally coupled pairs of Ce ions. Instead of a Currie-Weiss type behavior, the temperature dependence of magnetization M∼(T − TCrand)−0.8 with TCrand∼TQ∼3.3 K was deduced in a wide temperature range 5–800 K for various directions of external magnetic field, which indicates the Griffiths phase formation with nanosized clusters of magnetic ions in CeB6. Moreover, in contrast to the scenario of a single-ion Kondo lattice, when revealing the power-law behavior of the magnetic contribution ρm(T)∼T−0.4 to the resistivity in the range of 8–90 K, we conclude in favor of the regime of weak localization of charge carriers in CeB6. Fourier maps of electron density confirm the conclusion about the nanosized magnetic clusters of Ce ions in this archetypal strongly correlated electron system with unusual magnetic ground state.

Impact of green-emitting CaSc2O4:Ce3+ phosphor on the illuminance and color uniformity of white-light-emitting diodes

&lt;span&gt;blue light stimulation, a novel green phosphor, &lt;/span&gt;&lt;span lang="EN-GB"&gt;Ce&lt;sup&gt;3+&lt;/sup&gt;&lt;/span&gt;&lt;span&gt;-activated &lt;/span&gt;&lt;span lang="EN-GB"&gt;CaSc&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;&lt;/span&gt;&lt;span&gt;, was created, which emits green illumination with a maximum wavelength of 515 nm. Since the brightness performance of &lt;/span&gt;&lt;span lang="EN-GB"&gt;Ce&lt;sup&gt;3+&lt;/sup&gt;&lt;/span&gt;&lt;span&gt;-activated CaSc2O4 is equivalent to that of commercial phosphors such as &lt;/span&gt;&lt;span lang="EN-GB"&gt;Y&lt;sub&gt;3&lt;/sub&gt;Al&lt;sub&gt;5&lt;/sub&gt;O&lt;sub&gt;12&lt;/sub&gt;: Ce&lt;sup&gt;3+&lt;/sup&gt;&lt;/span&gt;&lt;span&gt;, it may be utilized as a substance for chroma transformation in white-light-emitting diodes (WLEDs) that comprise one blue LED, one green phosphor, as well as one red phosphor. The Ce ion is most likely at an eight-coordinated Ca position in the base crystal for said phosphor, which posesses orthorhombic CaFe&lt;/span&gt;&lt;sub&gt;&lt;span lang="EN-GB"&gt;2&lt;/span&gt;&lt;/sub&gt;&lt;span lang="EN-GB"&gt;O&lt;sub&gt;4&lt;/sub&gt;&lt;/span&gt;&lt;span&gt; configuration. The effect of burning temperature and dopant concentration on luminous strength was examined, and it was discovered that the optimal temperature and concentration reached 1,600 °C and 1 mol % Ce replaced in the Ca site, respectively. By substituting Mg for Ca, the luminous maximum wavelength moved towards greater values. Substituting Ca using Sr, on the other hand, and yielded changes towards lesser wavelengths.&lt;/span&gt;

Spatial uniformity of the spectral radiance by white LED-based K&lt;sub&gt;2&lt;/sub&gt;CaP&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;7&lt;/sub&gt;:Ce&lt;sup&gt;3+&lt;/sup&gt;, Tb&lt;sup&gt;3+&lt;/sup&gt; phosphor

The K2CaP2O7:Ce3+, Tb3+ (Ce/Tb-KCPO) phosphor with blue-to-green emission is introduced in this study. The synthesis of the phosphor is carried out with the solid-state approach. The phosphor characteristics, including X-ray diffraction, luminescence lifespan, and thermal stability are measured and examined. The data show that Ce/Tb-KCPO phosphor displays a broadband emission from blue to green when excited by ultraviolet source. Besides, the ion Ce3+ strengthen the emission of Tb3+ ion through an efficient energy-transfer mechanism, which is estimated about 82.51%. The main electric interaction responsible for this Ce/Tb energy transfer is the dipole-quadrupole one. The phosphor also benefits the luminous intensity and color uniformity of the light-emitting diodes (LED) white-light output. Therefore, the Ce/Tb-KCPO phosphor can be a potential material for high-power white light-emitting diodes (WLED).

Chemical and radiation shielding effectiveness of some heavy metal oxide glasses for immobilizing radioactive wastes

Ce/Sb/Mn different borate glass systems based PbO in concentrations of 50, 35, and 15 mol%, respectively, were prepared by the melting–annealing method. Wide chemical, structural, and radiation shielding characterizations were studied before and after 120 kGy of gamma radiation to test the possible use of glasses for immobilizing radioactive wastes. The results showed suitable density values ranging from 3.34 to 5.30 g/cm3 increased by irradiation. FTIR spectra revealed high structural stability against irradiation correlated to the trigonal BO3, tetrahedral BO4 groups, high polarizable Pb2+ ions, and the doped metal ions. Unexpectedly, the chemical durability after in situ leaching process in H2O, 0.1 N HCl, and 0.1 N NaOH for ~ 3 months revealed clear improving after irradiation e.g., enhanced by ~ 25% for Ce-lead borate glass. Scanning electron microscope (SEM) images of the glass surfaces revealed more smooth and homogenous surfaces after irradiation. Shielding parameters by Monte Carlo code (MCNP5) and Phy-X/PSD software were studied, e.g., mass and linear attenuation coefficients (MAC and LAC), effective atomic number (Zeff), radiation protection efficiency (RPE%), half and tenth value layers (HVL and TVL), and heaviness%. Comparing the shielding behavior of the three glasses revealed that Ce-lead borate glass has the highest values of LAC, MAC, Zeff, heaviness%, and RPE% and the lowest values of HVL, TVL, and MFP, referring to the best shielding efficiency. The whole study indicates the desired properties of glasses as immobilizers or containers for radioactive wastes, e.g., nuclear medicine units in hospitals, especially lead borate glass doped Ce ions.Graphical

Structure investigation of a Laponite-NaCl dispersion induced by desiccation in a confined geometry using SAXS

The drying of colloidal dispersions is a dynamic area that has many practical applications across a wide range of sectors. While most research focuses on the drying patterns formed after desiccation and the physical-chemical parameters that influence this process, the structure formed as a result of particle accumulation has received comparatively far less attention. In this work, an investigation of the structure formed after the drying of a 4% w/w Laponite - NaCl dispersion, with ionic force I=10−3M, in a confined geometry between two hydrophilic mica windows was performed. The desiccation was characterized by measuring the mass of the dispersion over time, until no further mass loss was detected. The sample shrank to the middle of the sample holder, and SAXS/WAXS experiments were conducted after complete drying to better understand the structure formed. Such experiments revealed the formation of clusters with various sizes, shapes, and anisotropic orientations, as well as the formation of structures with different crystalline orders that were not present in the initial sample. These structures were all quantified and interpreted on the basis of Laponite interparticle interactions, possible structured water that remained inside the dried sample even after drying ceased, and NaCl crystallization. Finally, the macroscopic consequence of the microstructure formed was observed in photographs using polarized optical microscopy. The results provided a better comprehension of the structure formed in concentrated Lap dispersions before as well as after drying, showing that X-ray scattering techniques can be useful to investigate the drying of a variety of other colloidal systems.

Metal Recovery from Natural Saline Brines with an Electrochemical Ion Pumping Method Using Hexacyanoferrate Materials as Electrodes.

The electrochemical ion pumping device is a promising alternative for the development of the industry of recovering metals from natural sources-such as seawater, geothermal water, well brine, or reverse osmosis brine-using electrochemical systems, which is considered a non-evaporative process. This technology is potentially used for metals like Li, Cu, Ca, Mg, Na, K, Sr, and others that are mostly obtained from natural brine sources through a combination of pumping, solar evaporation, and solvent extraction steps. As the future demand for metals for the electronic industry increases, new forms of marine mining processing alternatives are being implemented. Unfortunately, both land and marine mining, such as off-shore and deep sea types, have great potential for severe environmental disruption. In this context, a green alternative is the mixing entropy battery, which is a promising technique whereby the ions are captured from a saline natural source and released into a recovery solution with low ionic force using intercalation materials such as Prussian Blue Analogue (PBA) to store cations inside its crystal structure. This new technique, called "electrochemical ion pumping", has been proposed for water desalination, lithium concentration, and blue energy recovery using the difference in salt concentration. The raw material for this technology is a saline solution containing ions of interest, such as seawater, natural brines, or industrial waste. In particular, six main ions of interest-Na+, K+, Mg2+, Ca2+, Cl-, and SO42--are found in seawater, and they constitute 99.5% of the world's total dissolved salts. This manuscript provides relevant information about this new non-evaporative process for recovering metals from aqueous salty solutions using hexacianometals such as CuHCF, NiHCF, and CoHCF as electrodes, among others, for selective ion removal.

Sequential two photon absorption induced optical limiting action of oxide upconverter based MoS2 heterostructures

Lanthanide ions (Yb, Er) doped cerium oxide (CeO2) and yttrium oxide (Y2O3) upconverter nanoparticles were prepared by sol-gel synthesis technique. And the upconverter nanoparticles (CeO2: Yb, Er and Y2O3: Yb, Er) were made us heterostructure with MoS2 by hydrothermal synthesis. XRD confirms the formation of cubic phase of CeO2, cubic phase of Y2O3, hexagonal phase of MoS2 and their coexistence in heterostructures. Further, the observation of characteristic Raman peaks between 400 and 700 cm−1 (Raman modes of CeO2, Y2O3) and 300–400 cm−1 (Raman modes of MoS2) assured the formation of heterostructures. FESEM exposes that in heterostructures nanospheres (CeO2: Yb, Er) and nanospindle (Y2O3: Yb, Er) were dispersed on MoS2 nanoplatelets. Furthermore, when forming the heterostructure with MoS2, the diameter of the CeO2 nanosphere got increased (90 nm) whereas, the length of the Y2O3 nanospindle was decreased (166 nm). The maximum absorption band occurred at UV region due to the charge transition from O2− to Ce ion or Y ion for CeO2 (340 nm) and Y2O3 (274 nm) respectively. Both upconverters exhibits interesting luminescence behaviour with green emission (537 nm, 588 nm), blue emission (497 nm) and red emission (621 nm). Nonlinear absorption induced optical limiting action were examined by open aperture Z-scan technique using nanosecond pulse laser. All the prepared nanoparticles exhibit a reverse saturable absorption pattern ascribed due to sequential two photon absorption. Among, all the samples, MoS2–CeO2: Yb, Er and MoS2–Y2O3: Yb, Er heterostructure possess a high nonlinear absorption coefficient (16.76 × 10−10 m/W, 13.61 × 10−10 m/W) and low limiting threshold (0.33 × 1012 W/m2, 0.51 × 1012 W/m2) due to the strong inter-band collision between of MoS2 and upconverters. The absorption of high number of photons and low limiting threshold behaviour make MoS2–CeO2: Yb, Er and MoS2–Y2O3: Yb, Er heterostructures as potential candidate for the fabrication of optical limiter based laser safety devices.

Catalytic oxidation of toluene over highly dispersed Mn-Ce solid solutions synthesized with weakly acidic precursors

In this paper, a series of Mn-Ce composite oxide catalysts were prepared by different preparation methods using different Mn and Ce acidic precursors for the catalytic oxidation of toluene. The activity test results revealed that the Mn-Ce composite catalysts, synthesized through the sol-gel method using weakly acidic Mn acetate and Ce acetate as precursors, exhibited the highest performance for the catalytic oxidation of toluene. The T50 and T90 values for this catalyst were measured at 208 °C and 235 °C, respectively. The relatively weak acidity of manganese acetate and cerium acetate facilitates the presence of acidic -OH groups, which interact with the oxygen-negative charge sites on each other. Furthermore, during the calcination process, there was a strong interaction between hydrated Mn and Ce ions, resulting in the formation of highly dispersed metal oxide species. The formation of Mn-Ce solid solution demonstrated by Raman, XRD. The H2-TPR characterization indicated that the superior redox performance of the MnOx species on the catalyst surface played a pivotal role in achieving high activity. Moreover, the catalytic activity of the CeO2 species was further enhanced by employing the sol-gel method. XPS and O2-TPD results revealed a significantly higher amount of reactive oxygen species on the catalyst surface, which was identified as the primary reason for the increased activity. This study provides a new strategy for the selection of the catalyst precursors, thereby enhancing the catalytic activity of Mn-Ce composite oxides.

Rational design of Ce-doped CdS/N-rGO photocatalyst enhanced interfacial charges transfer for high effective degradation of tetracycline

The charge carrier separation efficiency and the adsorption capacity of the photocatalyst usually affect the degradation rate of antibiotics. Herein, Cerium-doped leaf-like CdS (Ce-CdS) modified with ultrathin N-doped rGO (N-rGO) composites were successfully constructed (Ce-CdS/N-rGO) to investigate the removal efficiency of tetracycline (TC). X-ray photoelectron spectroscopy (XPS) and photoelectrochemical results revealed that Ce ions doped in CdS acting as the electron capture sites facilitated the interfacial charge transfer. Theoretical calculation (DFT) results indicated that the interfacial effect between Ce-CdS and ultrathin N-rGO promoted the transfer of photogenerated electrons under the synergistic effect between the doping and interface modification strategy. The optimized Ce5-CdS/N-rGO20 composites had the maximum TC removal capability (94.5%) and maintained a stable cycling performance. In addition, the adsorption-driven photocatalytic degradation pathway of TC was studied through mass spectrometry (MS) and in-situ Fourier transform infrared spectroscopy (in-situ FTIR). This study will provide an effective strategy for the construction of efficient photocatalytic composites for wastewater treatment.

Ce-mediated molecular tailoring on gigantic polyoxometalate {Mo132} into half-closed {Ce11Mo96} for high proton conduction

Precise synthesis of polyoxometalates (POMs) is important for the fundamental understanding of the relationship between the structure and function of each building motif. However, it is a great challenge to realize the atomic-level tailoring of specific sites in POMs without altering the major framework. Herein, we report the case of Ce-mediated molecular tailoring on gigantic {Mo132}, which has a closed structural motif involving a never seen {Mo110} decamer. Such capped wheel {Mo132} undergoes a quasi-isomerism with known {Mo132} ball displaying different optical behaviors. Experiencing an ‘Inner-On-Outer’ binding process with the substituent of {Mo2} reactive sites in {Mo132}, the site-specific Ce ions drive the dissociation of {Mo2*} clipping sites and finally give rise to a predictable half-closed product {Ce11Mo96}. By virtue of the tailor-made open cavity, the {Ce11Mo96} achieves high proton conduction, nearly two orders of magnitude than that of {Mo132}. This work offers a significant step toward the controllable assembly of POM clusters through a Ce-mediated molecular tailoring process for desirable properties.

Optical properties and tunable luminescence of Ce3+/Dy3+ doped lithium borate glasses for photonic applications

Optical absorption and photoluminescence properties of novel lithium borate glasses, (B2O3)-(MO)-(Li2O)–(Bi2O3) where M stands for Ca, Mg or Sr, doped with Dy and Ce ions have been investigated. The fundamental optical absorption edge of these materials is observed in the region of 315–390 nm, and depends on the nature of alkaline-earth metals used as network modifiers. The photoluminescence spectra of Dy-doped glasses reveal two intensive emission bands in the visible range, which correspond to 4F9/2→6H15/2 (486 nm) and 4F9/2→6H13/2 (580 nm) transitions of Dy3+ ions. Ce-doped glasses show one broad band in the visible range, which corresponds to the 2D →2F5/2 (340 nm) transition of Ce3+ ions. Three photoluminescence lines (980 nm, 1010 nm and 1150 nm) attributed to the Dy3+ ions electronic transitions are observed in the near-IR region of the spectrum for Dy-doped glasses, while only one at 1150 nm is observed for the Dy/Ce co-doped glasses. Peculiarities of excitation energy transfer between rare-earth activator ions are discussed. These glasses are shown to be a promising host matrix for rare-earth doping.

Insight into the relationship between effective active sites and ultra-deep adsorption desulfurization performance of CuCeY with different Cu precursors

Adsorption desulfurization processes employing zeolites as sorbents are considered to be prospective desulfurization methods owing to their cost-effectiveness.Y zeolites modified with Cu and Ce have excellent adsorption capacity and selectivity for adsorption desulfurization. However, the effect of using different metal precursors on the active sites of these sorbents and their adsorption desulfurization performance still remains ambiguous, which impedes the development of improved desulfurization adsorbents. Herein, Cu(NO3)2, Cu(Ac)2, and CuSO4 were selected as Cu precursors to prepare a series of CuCeY from CeY zeolite. Desulfurization experimental results indicate that outstanding breakthrough adsorption capacities for thiophene (ca. 6.25 mg·g−1) with benzene as the solvent were achieved by the CuCeYA. The interaction between the CuCe metals was beneficial for enhancing the electron transfer between Cu2++Ce3+/Ce4++Cu+. Moreover, using different copper precursors significantly changed the redox ability of the adsorbent surface. Changing the copper precursor also had a significant effect on the locations of Cu and Ce ions, and using Cu(Ac)2 as a metal precursor facilitated the migration of Cu+ (53.6%) and cerium species (35.9%) to the supercage. In situ infrared characterization showed that the oligomerization of thiophene on CuCeYA was significantly restricted due to the lowest B acid content (11.85%) in the CuCeYA.

Effect of silane‐modified SiO2@Ce3+ nanoparticles on the mechanical property and anti‐corrosion for steel of the epoxy coating

AbstractIn this work, nano‐SiO2 have been used as nanocarriers for loading Ce(III) ions (SiO2@Ce3+). After loading, silane coupling agent has been used to modify these nanocarriers (m‐SiO2@Ce3+). Then, these modified nanocarriers were added as green inhibitors into the inner epoxy coating matrix, which was based on the epoxy resin (DER 671X75) and hardener (polyamide Epicure 3125). Morphological study by FE‐SEM showed that the spherical nanoparticles (m‐SiO2@Ce3+) were in size &lt; 100 nm and dispersed rather homogeneously into the polyme matrix. In addition, the addition of nanocarriers at a concentration of 2.5 wt.% into the epoxy polymer matrix enhanced significantly its mechanical property. Besides, the anticorrosion performance of the epoxy polymer matrix due to the presence of m‐SiO2@Ce3+ (at 2.5 wt. %) was proved by EIS analysis and salt spray tests.

Liquid Nitrogen Temperature Mechanoluminescence and Persistent Luminescence

AbstractAs novel stress‐sensing materials, the reported mechanoluminescence (ML) phosphors work only at or above room temperature. Herein, the ML response to low temperatures (77 K) is extended by employing ultra‐shallow traps. Strong ML stimulated by handwriting force followed by persistent luminescence is observed in BaSi2O2N2:Eu2+ (BSON) at 77 K. The UV pre‐irradiated BSON can still keep the characteristics of ML with 45% intensity after 300 min. Abundant ultra‐shallow traps with depth of ≈0.19 eV are found and revealed to be responsible for the low‐temperature ML and persistent luminescence. Manipulation of the ultra‐shallow traps is realized by doping Ge, Er, and Ce ions in BSON, leading to significant ML enhancement at 77 K. Together with ML, the ultra‐shallow traps also exhibit force memory ability to replicate the pre‐applied force pattern simply by afterglow. The finding advances the state‐of‐the‐art in force sensing under low temperature conditions.

Radioluminescence Processes in Cerium-Doped Silica Glasses

Rare-earth-doped silica glasses are promising materials for ionizing radiation dosimetry. In this paper, a bulk glassy silica doped with Ce ions, was prepared via the sol-gel technique and drawn at about 2000 °C into a cylindrical capillary rod. Under X-rays, this sample presents a radioluminescence (RL) signal that can be exploited for dose rate real-time monitoring with remarkable linear response spanning 6 decimal orders of magnitude. In order to elucidate RL signal dynamics associated with free carriers trapping-detrapping and recombination during and after X-ray irradiation, we studied the obtained RL signals using a kinetic model involving one or several trapping states and one recombination center. With this model and using appropriate sets of trapping parameters, extracted from the thermoluminescence data, the RL signal was numerically simulated, along with the populations of the relevant traps and centers. Several experimentally observed characteristics of the RL signals were explained using the model.

Regulating the Electronic Structure of Ni Sites in Ni(OH)2 by Ce Doping and Cu(OH)2 Coupling to Boost 5-Hydroxymethylfurfural Oxidation Performance.

Biomass is a sustainable and renewable resource that can be converted into valuable chemicals, reducing the demand for fossil energy. 5-Hydroxymethylfurfural (HMF), as an important biomass platform molecule, can be converted to high-value-added 2,5-furandicarboxylic acid (FDCA) via a green and renewable electrocatalytic oxidation route under mild reaction conditions, but efficient electrocatalysts are still lacking. Herein, we rationally fabricate a novel self-supported electrocatalyst of core-shell-structured copper hydroxide nanowires@cerium-doped nickel hydroxide nanosheets composite nanowires on a copper mesh (CuH_NWs@Ce:NiH_NSs/Cu) for electrocatalytically oxidizing HMF to FDCA. The integrated configuration of composite nanowires with rich interstitial spaces between them facilitates fast mass/electron transfer, improved conductivity, and complete exposure of active sites. The doping of Ce ions in nickel hydroxide nanosheets (NiH_NSs) and the coupling of copper hydroxide nanowires (CuH_NWs) regulate the electronic structure of the Ni active sites and optimize the adsorption strength of the active sites to the reactant, meanwhile promoting the generation of strong oxidation agents of Ni3+ species, thereby resulting in improved electrocatalytic activity. Consequently, the optimal CuH_NWs@Ce:NiH_NSs/Cu electrocatalyst is able to achieve a HMF conversion of 98.5% with a FDCA yield of 97.9% and a Faradaic efficiency of 98.0% at a low constant potential of 1.45 V versus reversible hydrogen electrode. Meanwhile, no activity attenuation can be found after 15 successive cycling tests. Such electrocatalytic performance suppresses most of the reported Cu-based and Ni-based electrocatalysts. This work highlights the importance of structure and doping engineering strategies for the rational fabrication of high-performance electrocatalysts for biomass upgrading.

Synthesis and photoluminescence properties of Ce3+ and Tb3+ doped Na3Gd(PO4)2 phosphors for white LEDs

Na3Gd(PO4)2 phosphors doped with rare-earth metal ions Ce3+ and Tb3+ were fabricated by the solid-state reaction method. Under the excitation of 340 nm light, the Ce3+-doped Na3Gd(PO4)2 phosphors exhibit a broad emission band ranging from 370 nm to 480 nm, which emitted blue light centered at 405 nm. When excited at 373 nm, the Tb3+-doped Na3Gd(PO4)2 phosphors presented a green light emission, including a strong peak located at 547 nm. In addition, both of the Na3Gd(PO4)2: Ce3+ and Na3Gd(PO4)2: Tb3+ phosphors showed excellent thermal stability at different temperatures, be specific in the Na3Gd(PO4)2: Ce3+ emission intensities at 150 °C could maintain about 84 % and the Na3Gd(PO4)2: Tb3+ could maintain about 92.9 % of those at room temperature. A prototype of the white light-emitting diodes lamp exhibiting bright white light was fabricated by using a 365 nm near-ultraviolet-emitting LED chip, combined with Na3Gd(PO4)2: Ce3+ blue phosphors, Na3Gd(PO4)2: Tb3+ green phosphors, and Na3Gd(PO4)2: Eu3+ red phosphors, which produced a high color rendering index of 89.4, and a relatively low correlated color temperature of 5496 K. Moreover, the CIE point was calculated to be at (0.3332, 0.3438), locating in the white light region. These results indicate that the as-prepared phosphors can be considered as potential candidates for ultraviolet/near-ultraviolet light-excited white light-emitting diodes applications.

Optimization of Neodymium Separation from Cerium and Samarium for Nuclear Fuel Burn-Up Determination

Sorption behavior of neodymium (Nd) from cerium (Ce) and samarium (Sm) on anion-exchange resins was investigated by column techniques. The anion exchange studies involved the sorption of Nd, Ce and Sm ions onto Dowex 1-X4 (100–200 mesh) in nitric acid – methanol medium. Separation of neodymium from cerium and samarium was carried out by column method to find out the best separation parameter condition with variating HNO3 concentration and weight of resin. The best elution profile was found using 0.3M HNO3 : methanol (1 : 9) as eluent through 1.25 grams of Dowex 1-X4 resin with 97.16 % Sm recovery and 95.59 % Nd recovery, while Ce was retained in the column.

Secondary Phase CeO2 Precipitates in Ce,Er-Doped Na0.5La0.5MoO4 Single Crystals Grown by Czochralski Method

Analytical scanning and transmission electron microscopy were used to study the microstructure of Ce,Er-doped Na0.5La0.5MoO4 laser crystals. Crystals were grown by the Czochralski method from the melts with a nominal composition of Na0.5La0.5−xCexEr0.005MoO4, where x = 0.125 and 0.15, then annealed at 700 and 1000 °C in the oxidizing atmosphere. We found the secondary phase precipitation of Ce2O3 oxide in as-grown crystals, while after high-temperature annealing the CeO2 precipitated crystals are always observed. Impurity ions Ce3+ occupy the La sites, and approximately 20% of the nominal Ce content is involved in the formation of Ce oxide secondary phase precipitates. The length of CeO2 precipitated crystals ranged between 100 nm and 550 nm (average length was 200 nm) and their width was 30–70 nm. The mechanism of CeO2 formation is discussed. The orientation relationships of Na0.5La0.5−xCexEr0.005MoO4/CeO2, the degree of coherence of the interface, and the preferential directions of their growth in the matrix were established. CeO2 crystals precipitated in the matrix cause light scattering with a wavelength comparable to the size of the precipitates and lead to deterioration of optical transparency of the material.

Ce-ZSM-5: A highly capable catalyst for the construction of acridines in water and their computational study against DNA gyrase protein.

Cerium doped ZSM-5 (Ce-ZSM-5) as an environmentally benign and reusable catalyst for the construction of acridines in aqueous medium. This method produced corresponding acridines with good yields and shorter reaction times. Also avoids the use of hazardous solvents and involves a simple work-up process. The solid catalyst was prepared by doping Ce ions with ZSM-5 (Zeolite Socony Mobil-5) and confirmed by XRD, BET SA-PSD and SEM. The synthesised acridine derivatives were confirmed by 1H NMR, 13C NMR and FTIR spectroscopic data. The docking studies of the synthesised compounds are performed by the PyRx auto dock tool against DNA gyrase protein. The products 5a and 6d are found to be the best fit ligands against DNA gyrase protein.