Synthesis,crystal structure and optical properties of a new beryllium borate,CsBe4(BO3)3

A novel beryllium borate CsBe₄(BO₃)₃ has been grown in crystals by high-temperature flux method using spontaneous nucleation technique for the first time. The crystal structure of this compound was determined by single crystal X-ray diffraction analysis. It crystallizes in the orthorhombic space group Pnma with lattice parameters a = 8.3914(5) Å, b = 13.3674(7) Å, c = 6.4391(3) Å, Z = 4, V = 722.28(7) Å³. The crystal takes the same structure type as Rb analog based on the units of BO₃ triangles and BeO₄ tetrahedrons, displaying a three-dimensional tunnel structure with Cs atoms filling in the cages. The IR spectrum confirms the presence of BO₃ groups and the UV–vis–IR diffuse reflectance spectrum exhibits this compound has a short UV cut-off edge below 200 nm. Band structures and density of states were calculated.     

Cu–Ce substituted cobalt nano ferrite - Structural,morphological, and magnetic behavior prepared by sol-gel auto-combustion

Sol-gel auto-combustion synthesized Co_1-xCu_xFe_2-yCe_yO₄ (x = 0.0, 0.25, 0.5 and 0.75; y = 0.0, 0.03, 0.06, and 0.09), Cu–Ce substituted Co ferrite nanopowders. Investigations have been done on how Cu–Ce substitution affects the structural and magnetic characteristics. The Cu–Ce substitution variation effect on structural and magnetic properties is studied with X-ray diffraction (XRD), Field effect scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Vibrating sample magnetometer (VSM). The XRD was used to identify the crystal phase, and the role of Cu–Ce substituted for Co indicates how it formed. There is no change in the crystal structure, and no additional characteristic peak linked to Cu²⁺ and Ce³⁺ ions substitution was found in the XRD. The powder was sintered at 1100 °C. The crystallite sizes were found in between 33 and 62 nm. Increasing the Cu–Ce content decreases the lattice constant and is found between 8.4044 and 8.3309 Å. The FESEM images were used to analyze the nanostructural properties. The range of 110–128 nm is the value of average grain size. Two vibrational bands can be seen in FTIR spectra at about 600 cm⁻¹ (v₁) and 400 cm⁻¹ (v₂). They are attributed to the spinel lattices A and B sites, respectively. The tetrahedral site has a greater vibrational frequency of 566.09 cm^−1, while the octahedral site has a lower vibrational frequency of 420.09 cm⁻¹. FTIR spectra show the tetrahedral stretching peaks shifting towards lower frequencies with increasing Cu²⁺ and Ce³⁺ ions content. At ambient temperature, the magnetic properties of Cu–Ce substituted cobalt ferrites revealed a strong hysteresis loop. There was a decrease in magnetic saturation and an increase in coercivity.     

A cyanide-containing cobalt(III) complex [Co(phen)2(CN)2][Co(phen)(CN)4]·4.5H2O: hydrothermal synthesis,crystal structure and spectroscopic properties

A cyanide-containing cobalt(III) complex, [Co(phen)₂(CN)₂][Co(phen)(CN)₄]?·?4.5H₂O (1: phen?=?1,10-phenanthroline) has been synthesized by hydrothermal techniques and characterized by elemental analyses, IR spectroscopy, UV–vis spectroscopy and single-crystal X-ray diffraction methods. The complex is triclinic, space group P 1 , with a?=?11.0047(16), b?=?12.9587(19), c?=?15.076(2)?Å, α?=?100.060(2), β?=?102.061(2), γ?=?91.803(2)°, V?=?2065.0(5)?ų, Z?=?2, and R ₁ [I?>?2σ(I)]?=?0.0481. The molecular unit of 1 consists of a cation/anion pair with interstitial water molecules in the crystal lattice. The combination of coordinative, hydrogen bonding and π–π stacking interactions results in the stabilization of a supramolecular solid-state architecture.     

Synthesis of high surface area CoAl2O4 and NiAl2O4 spinels by an alkoxide route

The mixed metal oxides CoAl₂O₄ and NiAl₂O₄ were prepared in a high surface area form by using a sol-gel method which involves hydrolysis of cobalt-aluminium and nickel-aluminium isopropoxides. The resulting gels were calcined at 673 K to yield the corresponding spinel-type metal oxides. Powder X-ray diffraction was used to confirm spinel formation. Nitrogen adsorption-desorption measurements have shown the materials obtained to be highly porous. The BET surface area was found to be 240 m²g⁻¹ for CoAl₂O₄ and 255 m²g⁻¹ for NiAl₂O₄. Both materials showed a unimodal distribution of pore radii, where the most frequent pore radius is 5 nm for cobalt aluminate and 3 nm for nickel aluminate.     

Synthesis,growth, structure and characterization of nickel(II)-doped hexaaquacobalt(II) dipotassium tetrahydrogen tetra-o-phthalate tetrahydrate crystals

Single crystals of K₂[Co_(1−x)Ni_x(H₂O)₆] (C₈H₅O₄)₄·4H₂O (x = 0.25) (PCNHP), a semiorganic black colored transparent crystal of size ∼20 × 13 × 4 mm³, are grown from an aqueous solution of potassium hydrogen phthalate enriched with cobalt chloride and nickel chloride by slow evaporation solution growth technique at room temperature. Structural analysis by single crystal X-ray diffraction reveals that the crystal belongs to monoclinic system with space group P2₁/c and the cell parameters are a = 10.41(3) Å, b = 6.84(2) Å, c = 29.46(9) Å, Z = 4. Incorporation of both Co(II) and Ni(II) into the potassium hydrogen phthalate (KHP) crystal lattice is well confirmed by EDS and chemical tests. Powder XRD profiles indicate the crystallinity and FT-IR studies reveal the vibrational patterns. The UV–vis optical absorption spectrum of PCNHP shows the lower optical cut-off at ∼300 nm and the crystal was transparent in the entire visible region. The crystalline perfection of the grown crystal analysed by high-resolution X-ray diffraction (HRXRD) analysis reveals that the diffraction curve (DC) contains multi-peaks with low angular spread indicating the possibility of low angle structural grain boundaries. Scanning electron microscope (SEM) studies indicate the structure defect centers. The dielectric, thermal and mechanical behaviors of the specimen were also investigated.     

Structural,optical and photocatalytic activity of cerium doped zinc aluminate

Zinc aluminate and cerium-doped zinc aluminate nanoparticles are synthesised by co-precipitation method. Ammonium hydroxide is used as a precipitating agent. The synthesised compounds are characterised by powder X-ray diffraction (XRD), Fourier transform Infrared spectroscopy (FT-IR), Ultraviolet diffuse reflectance spectroscopy (UV-DRS), Thermogravimetric analysis (TGA), Scanning electron microscopy (SEM) and Surface area measurements. The photocatalytic activity of zinc aluminate and cerium doped zinc aluminate nanoparticles are studied under the UV light and visible light taking methylene blue as a model pollutant. The amount of catalyst, concentration of dye solution and time are optimised under UV-light. Degradation of methylene blue under the UV-light is found to be 99% in 20 min with 10 mg of cerium doped catalyst. Compared to visible light degradation, the degradation of dye under UV-light is higher. Cerium doping in zinc aluminate (ZnAl₂O₄:Ce³⁺) increased the photocatalytic activity of zinc aluminate.     

Structure and optical properties of [Ba1–xY2x/3](Zr0.25Ti0.75)O3 powders

[Ba_1–xY_2x/3](Zr_0.25Ti_0.75)O₃ powders with different yttrium concentrations (x = 0, 0.025 and 0.05) were prepared by solid state reaction. These powders were analyzed by X-ray diffraction (XRD), Fourier transform Raman scattering (FT-RS), Fourier transform infrared (FT-IR) and X-ray absorption near-edge (XANES) spectroscopies. The optical properties were investigated by means of ultraviolet–visible (UV–vis) absorption spectroscopy and photoluminescence (PL) measurements. Even with the addition of yttrium, the XRD patterns revealed that all powders crystallize in a perovskite-type cubic structure. FT-RS and FT-IR spectra indicated that the presence of [YO₆] clusters is able to change the interaction forces between the O–Ti–O and O–Zr–O bonds. XANES spectra were used to obtain information on the off-center Ti displacements or distortion effects on the [TiO₆] clusters. The different optical band gap values estimated from UV–vis spectra suggested the existence of intermediary energy levels (shallow or deep holes) within the band gap. The PL measurements carried out with a 350 nm wavelength at room temperature showed that all powders present typical broad band emissions in the blue region.     

Synthesis of the Dy: SrMoO4 with High Photocatalytic Activity under Visible Light Irradiation

Dysprosium (Dy)‐doping SrMoO₄ (with different molar ratio of Dy/Sr = 0/100, 10/100, 15/100 and 20/100) have been synthesized by high temperature thermal decomposition of metal–organic salt in organic solvent with a high boiling point. Their structures, morphology, and optical properties were characterized by X‐ray diffraction (XRD), high‐resolution tuning electron microscopy ((HR)TEM), X‐ray photo‐electron spectroscopy (XPS), and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). Using this method, the pure phase, nano‐size, and low band gap of SrMoO₄ sample are obtained. The results shows that the size of as‐synthesized SrMoO₄ nanoparticles was about 200 nm. The band gap of Dy‐doped SrMoO₄ ranges from 3.76–3.90 eV, and decreases with increasing Dy concentration. The photocatalytic performance of as‐syntheszied products were determined from the degradation of methylene blue (MB) by UV–vis light irradiation. The 15 mol%Dy‐doped SrMoO₄ sample shows the best performance for photocatalytic degradation of methyl blue of nearly 100% in 120 min under visible irradiation, which is higher than most of those reported before. The present work is meaningful for revealing the underlying mechanism in photocatalyst and improving the photocatalytic performance.     

Ultrasound assisted synthesis of starch-capped Cu2O NPs towards the degradation of dye and its anti-lung carcinoma properties

A unique starch encapsulated Cu₂O nanoparticles were synthesized through a simple and ‘green’ route using ultrasonic irradiation. The polar functional groups on the starch (OH) facilitate the NP capping and stabilization. Structural features of the material were assessed over several advanced techniques like fourier transformed infra-red (FT-IR), UV–vis spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), energy dispersive X-ray analysis (EDX) elemental mapping, transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. It was catalytically explored in reducing an organic dye (Methylene blue - MB) in the presence of NaBH₄ at ambient conditions, being monitored in a UV–vis spectrophotometer. The nanocatalyst was recycled 11 times keeping consistency in its reactivity. Biologically, the nanocomposite exhibited excellent cytotoxicity against lung adenocarcinoma (PC-14, LC-2/ad and HLC-1) cell lines without affecting the normal (HUVEC) cell line. IC₅₀values of the nanocomposite were found at 618, 56 and 379 against HLC-1, LC-2/ad, and PC-14 cell lines respectively and accordingly, PC-14 afforded the best adenocarcinoma activity.     

Synthesis,characterization of nanosized CoAl<Subscript>2</Subscript>O<Subscript>4</Subscript> and its electrocatalytic activity for enhanced sensing application

Nanosized cobalt aluminate (CoAl₂O₄) was prepared by thermolysis of heteronuclear coordination compound, namely [Al₂Co(C₂O₄)₄(OH₂)₆]. The synthesized precursor was characterized by chemical analysis, vibrational spectra and thermal analysis. The cobalt aluminate obtained after a heating treatment of the precursor at 700 °C was characterized by IR, XRD, TEM coupled with SAED measurements. Two types of carbon-based electrodes, glassy carbon and boron-doped diamond electrodes were decorated with the obtained cobalt aluminate in order to enhance the electroanalytical performance for the tetracycline (TC) detection in the aqueous solutions. Cyclic voltammetry technique was used to determine the effect of the nanosized CoAl₂O₄ on the electrochemical oxidation of TC and as consequence, for TC detection at both carbon-based electrodes. The obtained cobalt aluminate exhibited the electrocatalytic activity toward TC detection in direct relation with the type of the carbon substrate, which allowed enhancing the electroanalytical parameters of TC detection in the aqueous solution.     

Facile synthesis and characterization of β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide as novel nanocomposites for efficient photocatalytic degradation of methylene blue dye

In this paper, our research team has synthesized new nanocomposites by simple precipitation/ignition method and using low-cost chemicals. Hence, β-cobalt hydroxide/hydrohausmannite/ramsdellitee/spertiniite and tenorite/cobalt manganese oxide/manganese oxide new nanocomposites were synthesized by precipitation of Mn(II)/Co(II)/Cu(II) solution using sodium hydroxide and ignition of precipitate at 700 °C for 3 hrs, respectively. The synthesized nanocomposites were characterized using different instruments such as energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), nitrogen gas sorption analyzer, and UV–vis spectrophotometer. Energy dispersive X-ray analysis revealed that the nanocomposite formed as a result of precipitation consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.73, 27.01, 17.26, and 24 %, respectively. Also, the nanocomposite formed as a result of ignition consists of copper, cobalt, manganese, and oxygen where the weight percentages are equal to 31.26, 23.87, 14.56, and 30.31 %, respectively. Transmission electron microscope revealed that the nanocomposites formed as a result of precipitation and ignition consist of polyhedral and spherical shapes with an average diameter of 34.50 and 28.56 nm, respectively. The synthesized nanocomposites were used as new photocatalysts for the efficient degradation of methylene blue dye. 0.05 g of the synthesized nanocomposites degrade 100 % of 50 mL of 15 mg/L of methylene blue dye solution within 25 min in the presence of H₂O₂ under UV light.     

Synthesis and characterization of magnetite nanoparticles for photocatalysis of nitrobenzene

The present work shows the photocatalytic degradation of nitrobenzene (NB) using Fe₃O₄ magnetic nanoparticles (MNP) as a photocatalyst in the presence of UV light. The MNP were synthesized by an ultrasonic-assisted reverse co-precipitation (US-RP) method using FeSO₄, FeCl₃ and NH₄OH as precursors. The prepared nanoparticles were characterized by UV–vis spectroscopy, attenuated total reflectance Fourier transformed infrared spectroscopy (ATR FT-IR), Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), Zeta potential, Vibrating sample magnetometer (VSM) and Magnetic thermogravimetric analysis (MTGA). The successive decrement in the absorbance at 265 nm shows the effective decrease in NB concentration measured by UV–vis spectroscopy. The reaction intermediates detected by gas chromatography/mass spectrum (GC/MS) were 2-nitrophenol (2-NPh), 3-nitrophenol (3-NPh) and 4-nitrophenol (4-NPh). The prepared MNP showed an optimal NB degradation at an initial pH of 2 and 100 ppm of the photocatalyst.     

Synthesis,spectroscopic studies and structures of square-planar nickel(II) and copper(II) complexes derived from 2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol

Two new nickel(II) [Ni(L)₂] and copper(II) [Cu(L)₂] complexes have been synthesized with bidentate NO donor Schiff base ligand (2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol) (HL) and both complexes Ni(L)₂ and Cu(L)₂ have been characterized by elemental analyses, IR, UV–vis, ¹H, ¹³C NMR, mass spectroscopy and room temperature magnetic susceptibility measurement. The tautomeric equilibria (phenol-imine, O–H?N and keto-amine, O?H–N forms) have been systemetically studied by using UV–vis absorption spectra for the ligand HL. The UV–vis spectra of this ligand HL were recorded and commented in polar, non-polar, acidic and basic media. The crystal structures of these complexes have also been determined by using X-ray crystallographic techniques. The complexes Ni(L)₂ and Cu(L)₂ crystallize in the monoclinic space group P2₁/n and P2₁/c with unit cell parameters: a = 10.4552(3) Å and 12.1667(4) Å, b = 8.0121(3) Å and 10.4792(3) Å, c = 13.9625(4) Å and 129.6616(3)Å, V = 1155.22(6) Å³ and 1155.22(6) Å³, D_x = 1.493 and 1.476 g cm^?3 and Z = 2 and 2, respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares to a find R = 0.0377 and 0.0336 of for 2340 and 2402 observed reflections, respectively.     

Nano lithium aluminate filler incorporating gel lithium triflate polymer composite: Preparation,characterization and application as an electrolyte in lithium ion batteries

Gel polymer composites electrolytes containing nano LiAlO₂ as filler were prepared using a solution cast technique and characterized using different techniques such as X-ray diffraction (XRD), thermal analysis (TG, DSC), Fourier transform infra – red spectroscopy (FT-IR) and scanning electron microscope (SEM). X-ray diffraction analysis showed the effect of lithium tri fluoro methane sulphonate (LiCF₃SO₃), poly vinyl acetate (PVAc) and nano lithium aluminate (LiAlO₂) on the crystalline structure of the poly vinylidene fluoride –co– hexa fluoro propylene (PVDF-co-HFP) matrix containing ethylene carbonate (EC) and diethyl carbonate (DEC) as plasticizers. FT-IR analysis confirmed both the good dissolution of the LiCF₃SO₃ salt and the good interaction of the nano LiAlO₂ filler with the polymer matrix. TG analysis showed the good thermal stability of the LiAlO₂ samples compared to the free one. Also, addition of nano LiAlO₂ filler enhanced the conductivity value of the polymer composites electrolytes. The sample containing 2 wt% of LiAlO₂ showed the highest conductivity value, 4.98 × 10⁻³ Ω ⁻¹ cm⁻¹ at room temperature, with good thermal stability behavior (T_d = 362 °C). This good conductive and thermally stable polymer nano composite electrolyte was evaluated as a promising membrane for lithium ion batteries application.     

Syntheses,characterization and nonlinear optical properties of sodium–scandium carbonate Na5Sc(CO3)4·2H2O

A novel nonlinear optical (NLO) material Na₅Sc(CO₃)₄·2H₂O has been synthesized under a subcritical hydrothermal condition. The structure is determined by single-crystal X-ray diffraction and further characterized by TG analyses and UV–vis–NIR diffuse reflectance spectrum. It crystallizes in the tetragonal space group P-421c, with a = b = 7.4622(6) Å, C = 11.5928(15) Å. The Second-harmonic generation (SHG) on polycrystalline samples was measured using the Kurtz and Perry technique, which indicated that Na₅Sc(CO₃)₄·2H₂O was a phase-matchable material, and its measured SHG coefficient was about 1.8 times as large as that of d₃₆ (KDP). The results from the UV–vis diffuse reflectance spectroscopy study of the powder samples indicated that the short-wavelength absorption edges of Na₅Sc(CO₃)₄·2H₂O is about 220 nm, suggesting that this crystal is a promising UV nonlinear optical (NLO) materials.     

Hydroflux synthesis and crystal structure of new lanthanide tungstate oxyhydroxides

Single crystals of Na₅Ln(OH)₆WO₄ where Ln = Er, Tm, and Yb were grown out of a NaOH hydroflux. The crystals were characterized by single crystal X-ray diffraction and were found to crystallize in the monoclinic space group I2/a. The lattice parameter ranges for the three structures are a = 11.2024(7) Å–11.2412(6) Å, b = 16.1850(10) Å–16.2220(10) Å, and c = 11.9913(7) Å–12.0323(7) Å while the β angle range is 101.999(2)°–102.025(2)°.     

Synthesis,structural and magnetic characterisation of MIL 36, Co(C7H10O4), a three-dimensional coordination polymer

Hydrothermal reaction of cobalt (II) salts with pimelate ions produces the new compound Co(C₇H₁₀O₄). It crystallises in the orthorhombic space group Pcca 〚a = 37.477 8(8) Å, b = 4.772 4(1) Å, c = 9.330 2(1) Å〛 and its structure was solved by single crystal X-ray diffraction. The neutral three-dimensional framework is built up from isolated cobalt tetrahedra bridged by pimelate ions. The connection involves the formation of two types of small channels. Magnetic measurements indicate a paramagnetic behaviour down to 20 K, the temperature at which magnetic susceptibility decreases due to the appearance of antiferromagnetic interactions. Co–CO₂–Co linkages give rise to infinite two-dimensional networks pillared by pimelate chains. ‘Super-superexchange’ via bridging carboxylate groups explains the low magnetic ordering temperature. Co(C₇H₁₀O₄), is denoted MIL-36 for Materials of Institut Lavoisier.     

Facile synthesis and characterization of copper oxalate/cobalt oxalate/manganese oxalate and copper oxide/cobalt manganese oxide/manganese oxide as new nanocomposites for efficient photocatalytic degradation of malachite green dye

Scientists seek to synthesize new catalysts with simple methods to treat water pollution from organic dyes using photocatalytic degradation technology. In this technology, when light falls on the catalyst, the produced hydroxyl free radicals convert the dye into non-toxic gases such as CO₂ and H₂O. So, in this work, copper oxalate/cobalt oxalate/manganese oxalate (Abbreviated as P₁) and copper oxide/cobalt manganese oxide/manganese oxide (Abbreviated as P₂) new nanocomposites were fabricated via precipitation of Cu²⁺/Co²⁺/Mn²⁺ solution using oxalic acid and ignition of precipitate at 550 °C for 4 hrs, respectively. Some tools, involving X-ray diffraction (XRD), UV–vis spectrophotometer, energy dispersive X-ray spectroscopy (EDX), nitrogen gas sorption analyzer, transmission electron microscope (TEM), and field emission scanning electron microscope (FE-SEM), were used for characterizing the fabricated nanocomposites. The EDX spectra confirmed that the P₁ composite consist of C (26.28 %), oxygen (46.66 %), manganese (7.27 %), cobalt (7.59 %), and copper (12.20 %). Also, the P₂ composite consist of oxygen (8.23 %), manganese (31.34 %), cobalt (27.19 %), and copper (33.24 %). A transmission electron microscope shows that the P₁ and P₂ composites consist of polyhedral and spherical shapes with an average diameter of 28.13 and 14.37 nm, respectively. The BET surface area, average pore size, and total pore volume of the P₁ composite are 29.0725 m²/g, 2.0749 nm, and 0.0302 cc/g, respectively. Besides, the BET surface area, average pore size, and total pore volume of the P₂ composite are 58.1088 m²/g, 1.6087 nm, 0.0467 cc/g, respectively. 60 mg of the synthesized nanocomposites completely decompose 60 mL of 15 mg/L of malachite green dye solution within 20 min in the presence of hydrogen peroxide and UV light. The synthesized catalysts outperformed many other catalysts published in previous studies.     

Copper(II)–malonato coordination frameworks with ethanolammonium cations. Synthesis,spectral, thermal and structural characterization of trans-[Cu(mal)2(meaH)2] and {(deaH)2[Cu(μ-mal)2]·H2O}∞ (meaH=monoethanolammonium,deaH=diethanolammonium and mal=malonate)

Two isomorphous malonato–copper(II) complexes, [Cu(mal)₂(meaH)₂] and {(deaH)₂[Cu(μ-mal)₂]·H₂O}_∞ (meaH=monoethanolammonium, deaH=diethanolammonium and mal=malonate), have been prepared and characterized by elemental analyses, IR, UV–vis, magnetic measurements and single crystal X-ray diffraction. The mononuclear complex crystallizes in the monoclinic space group P2₁/n, with a=8.6630(8) Å, b=7.5122(5) Å, c=11.4390(10) Å, β=95.530(7) and Z=2. The polymeric malonato-bridged copper(II) complex crystallizes in the monoclinic space group P2₁/c, with a=26.5169(14) Å, b=8.2544(5) Å, c=9.5243(5) Å, β=96.256(4) and Z=4. The monomeric complex consists of individual units in which copper(II) sits on the inversion center and is octahedrally coordinated by two bidentate mal and two monodendate meaH ligands. The structural units are joined into the framework by the system of hydrogen bonds. The polymeric complex composed of two-dimensional chains containing the mal bridged [Cu(mal)₂]²⁻ ions and each mal ligand simultaneously exhibits chelating bidentate (at one copper atom) and bridging (at the adjacent copper atom) coordination modes. The intrachain Cu1⋯Cu2 separation is 6.302(4) Å. The deaH cations are not coordinated to copper(II) and occupy the voids of the frame work, together with the lattice water molecules. The IR spectra and thermal decompositions of both complexes are described in detail.     

Effects of nano-YAG (Y3Al5O12) crystallization on the structure and photoluminescence properties of Nd3+-doped K2O–SiO2–Y2O3–Al2O3 glasses

Nd³⁺-doped precursor glass in the K₂O–SiO₂–Y₂O₃–Al₂O₃ (KSYA) system was prepared by the melt-quench technique. The transparent Y₃Al₅O₁₂ (YAG) glass–ceramics were derived from this glass by a controlled crystallization process at 750 °C for 5–100 h. The formation of YAG crystal phase, size and morphology with progress of heat-treatment was examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transformed infrared reflectance spectroscopy (FT-IRRS). The crystallite sizes obtained from XRD are found to increase with heat-treatment time and vary in the range 25–40 nm. The measured photoluminescence spectra have exhibited emission transitions of ⁴F_3/2 → ⁴I_J (J = 9/2, 11/2 and 13/2) from Nd³⁺ ions upon excitation at 829 nm. It is observed that the photoluminescence intensity and excited state lifetime of Nd³⁺ ions decrease with increase in heat-treatment time. The present study indicates that the incorporation of Nd³⁺ ions into YAG crystal lattice enhance the fluorescence performance of the glass–ceramic nanocomposites.