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In this research, solvothermal synthesized MoSe2 nanosheets were analyzed to determine their structure and optical properties. Measurements through atomic force microscopy, scanning electron microscopy, and transmission electron microscopy confirmed the formation of MoSe2 nanosheets. The energy-dispersive x-ray results revealed the presence of high-purity MoSe2 and an atomic percentage ratio of Mo:Se ∼ 1:1.93. Additionally, x-ray diffraction and Raman showed the crystal structure of MoSe2 and the existence of a two-dimensional (2D) layer, respectively. The linear optical properties of the MoSe2 nanosheets were analyzed by Fourier transform infrared (FTIR) spectroscopy and the Kramers–Kronig method. The FTIR research indicated the vibrational modes of several chemical groups, thus proving the presence of MoSe2 ions. For the varying concentrations of MoSe2 nanosheets in dimethylformamide, the third-order nonlinear optical properties of MoSe2 nanosheets were determined in detail using the Z-scan approach and a continuous-wave Nd:YAG laser. As the transmittance measurements in an open aperture Z-scan setup indicated, all the synthetized samples had saturable absorption. Similar investigations using a close-aperture Z-scan technique proved that all samples had nonlinear refractive indices in the range of 10−7 cm2/W with a positive sign and self-focusing behavior. Moreover, the third-order susceptibility and the figure of merit were found to be in the order of 10−5 esu and 10−4 esu cm, respectively. The findings of this study provide insight about modified 2D materials and expand the use of MoSe2 nanosheets in photonic devices. [ABSTRACT FROM AUTHOR]

In this research, Zn(1−x)CrxAl2O4 (x = 0.00, 0.05, 0.10, 0.20) nanoparticles were prepared by a simple and green chemistry synthesis using gelatin as a polymerization agent. X-ray diffraction technique and scanning electron microscopy imaging were used to analyze the structural and morphological properties of the samples. X-ray diffraction results revealed that all samples were polycrystalline and crystallized in a cubical spinel phase. With increasing the x from 0.00 to 0.20, the main Bragg peaks shift to smaller angles, and the crystallite size and energy bandgap of samples decrease as well. The nonlinear absorption coefficient, β, and nonlinear refractive index, n2, of Zn(1−x)CrxAl2O4 were meticulously studied by the Z-scan approach. The orders of n2 and β are 10−7 and 10−4 cm/W, respectively. The saturable absorption and the self-defocusing effect are the main factors in the appearance of β and n2, respectively. The experimental results confirmed that increasing the percentage of Cr caused nonlinear coefficients to increase. [ABSTRACT FROM AUTHOR]

In this research, manganese ferrite (MnFe2O4) thin film and spherical nanoparticles were synthesized using the e-beam evaporation type of PVD and sol-gel method, respectively. Also, the effect of morphology on the structural, linear, and nonlinear optical properties of samples was investigated. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to assess the surface morphology of the specimens. The nonlinear optical (NLO) properties were also explored by the Z-scan technique utilizing CW laser at 532 nm. Different incident powers of laser were evaluated during nonlinearity assessments. In this research, MnFe2O4 nanoparticles showed higher nonlinear responses than MnFe2O4 thin film. The nonlinear refractive (NLR) indices and nonlinear absorption (NLA) coefficient of MnFe2O4 nanoparticles were 10−4 cm2/W and 10 W/cm, respectively. The obtained optical nonlinearity can be assigned to the two-photon absorption and the self-focusing effect. In addition, thermal nonlinearity explains the changes in the value of β and n2 for MnFe2O4 nanoparticles and thin films. The higher nonlinearity in the nanoparticle sample than thin film can be due to nanoparticle clusters in solution of MnFe2O4. The good nonlinear optical properties of MnFe2O4 indicate that this material can be the promising potential in nonlinear photonic devices. [ABSTRACT FROM AUTHOR]

In this research, γ-Al2O3 nanoparticles (NPs) were synthesized by using the sol–gel process. The photon attenuation properties of these NPs were obtained by measuring the linear and mass attenuation coefficients (μl, μm) at different photon energies. In addition, the theoretical values of μm for γ-Al2O3 micro-particles were calculated using the WinXCom computer program and compared with the experimental values of μm for NPs of γ-Al2O3. Furthermore, in order to evaluate the impact of γ-irradiation on these NPs, the experimental values of μl and μm for γ-Al2O3 NPs, before and after receiving 20 kGy dose of γ-irradiation, were investigated. It was observed that μm of γ-Al2O3 NPs decreases after receiving γ-irradiation because of increasing the photon's energy, which indicates the changes in the molecular structure of NPs after γ-irradiation. Moreover, the structural properties of NPs were evaluated by UV–Vis spectroscopy, x-ray diffraction patterns, and scanning electron microscopy images. UV–Vis spectroscopy showed an absorption peak at 212.5 nm before γ-irradiation, and the absorption peak of NPs disappeared when γ-irradiation was started. The average crystalline size was determined to be 3.65 nm in the sample before γ-irradiation and 9.29 nm in the sample with the maximum dose of 20 kGy. The results of scanning electron microscopy show an increase in particle size from 6.5 nm in a non-irradiated sample up to 9 nm in a sample with the highest γ-irradiation dose. [ABSTRACT FROM AUTHOR]

In this research, the linear and nonlinear optical properties of La2−xSrxCoO4 (x = 0.5, 0.7, 0.9, 1.1, 1.3 and 1.5) nanoparticles were investigated. The structure and nanoscale morphology of the synthesized samples were confirmed by XRD analysis and FE-SEM imaging, respectively. Optical transmission, reflection and absorption studies were conducted to analyze the optical constants of the nanopowders. The obtained results revealed that the optical band gap energy decreased with the increase of Sr doping from 4.25 eV for x = 0.5 to 3.65 eV for x = 0.9. The enhancement trend is observed for the refractive and extinction coefficients with increasing Sr contents from x = 0.5 to x = 0.9 using the Kramers–Kronig approach. Third-order nonlinear optical susceptibility, nonlinear refractive (NLR) index, and nonlinear absorption (NLA) values were evaluated using the Z-scan technique. The NLA (as two phonon absorption (TPA)) and NLR responses have the highest amount of transmittance (62.28 × 10−7 cm W−1 and 8.16 × 10−11 cm2 W−1) for x = 0.9 and the lowest amount of transmittance (7.52 × 10−7 cm W−1 and 2.7 × 10−11 cm2 W−1) for x = 0.5, respectively. These results could be due to the strong hybridization of Co-3d and O-2p orbitals which is caused by enhancement of Co3+-LS populations with increasing Sr doping content from x = 0.5 to 0.9. As the Sr doping content increased from x = 0.9 to x = 1.5, the Co3+ spin state transition from LS to IS leads to decrease of the refractive index, extinction coefficient, and NLA and NLR responses of La2−xSrxCoO4 compounds. The excellent nonlinear properties of La2−xSrxCoO4 nanoparticles indicate that these compounds are good candidates for optical devices and can also provide a reference for the synthesis of new optical materials. [ABSTRACT FROM AUTHOR]

We report the third-order nonlinear optical (NLO) properties of ZnO@C-N composite microspheres and pure ZnO which have been investigated with the Z-scan technique under continuous wave laser. ZnO@C-N composite microspheres have been hydrothermally synthesized at two different precursor concentrations to have structures at different impurity levels. Moreover, pure ZnO is prepared under the annealing process. The nonlinear optical absorption of samples was measured by using the open-aperture Z-scan technique and was evaluated relating to the two-photon absorption (TPA) mechanism. Moreover, both ZnO@C-N and ZnO microstructures exhibited a negative nonlinear refractive index (NLR) referring to the self-defocusing effect. The order of the (NLR) value, is about 10 -10 (cm 2 /W) and, the NLA coefficients of specimens are in the order of 10 -5 (cm/W). The NLA coefficient has a similar behavior as the NLR versus increasing incident intensity of the laser. The results show that the nonlinearity response of ZnO@C-N composites is higher than the pure ZnO and ZnO@C-N at higher precursor concentrations exhibits the maximum amount of NLA and NLR coefficients compared to other samples. This observation which is attributed to the change in optical and structural properties of material due to impurity presence, underscores the presence of impurity for engineering materials to improve the nonlinearity properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A variety of new inorganic and organic materials have emerged to advance laser technologies and optical engineering. A rational design approach can contribute significantly to fabricating nonlinear optically active metal-organic frameworks (MOFs) by considering the underlying structure-property linkage. Here, it has been embarked on a study of novel samarium(III) MOF, ([Sm 2 (ata) 3 (DMF) 4 ]·DMF (ata 2- : 2-aminoterephthalate), abbreviated as NH 2 -Sm-MUM-4) with enhanced nonlinear optical (NLO) properties. The crystal structure of this MOF represents a 6-connected framework with a pcu topology and distinctive characteristics, including open metal sites, free amine groups, and great stability, making it suitable for third-order NLO activity. The nonlinear index of refraction ( n 2 ) revealed the self-focusing impacts of NH 2 -Sm-MUM-4 at different incident intensities. The highest value of n 2 and β related to 10 mw power of incident intensity are 5.15 cm 2 /W and 2.65 cm/W, respectively. As far as the authors know, this is the first study examining the potential systematic structural-property associations in Sm-MOFs considering improved third-order NLO properties.

Through one-pot hydrothermal synthesis, we synthesized VSe 2 -CoSe 2 nanostructures with a distinctive flower-like morphology. The structural characterizations were conducted using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FTIR). By modulating the proportion of the CoSe 2 phase, we transformed these hybrid nanostructures into nanoparticles, thereby influencing their nonlinear optical properties. The third-order nonlinear optical parameters ( n 2 and β ) were rigorously examined via the precise Z-scan technique under various laser power conditions. The nanostructures demonstrated a self-focusing refractive response and exhibited pronounced two-photon absorption during the nonlinear absorption process. The magnitudes of n 2 and β were determined to be in the order of 10 -8 (cm 2 W -1 ) and 10 -4 (cm W -1 ), respectively. The exceptional figure of merit (FOM) of these composite flower-like structures underscores their superior nonlinear optical characteristics, establishing them as promising candidates for photonic applications, particularly in optical switching devices., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The study unveiled an innovative strategy for precise radiation targeting in cancer treatment, along with the monitoring of molecular changes induced by this therapeutic approach. In this research, we explored the impact of administering anti-HER2-AgNPs nanoconjugates either individually or in conjunction with gamma irradiation on the viability of SKBR3 breast cancer cells. The utilization of nanoconjugates resulted in an enhancement of cellular sensitivity toward radiation. The viability of the cells exhibited a decline as the dose of irradiation increased, and this decrease was further exacerbated by the passage of time following irradiation. The analysis of RS revealed distinct cellular responses in varying conditions. The observed increase in SERS intensity, resulting from the increment in dose from 0 to 2 Gy, can be attributed to the probable upregulation of HER2 expression induced by irradiation. The observed decrease in SERS intensity at doses of 4 and 6 Gy can be attributed to the likely reduction in HER2 expression. It was illustrated that the analysis of Raman spectroscopy data can aid in the identification of radiation-induced biochemical alterations in cancer cells during the application of nanoconjugates-based radiotherapy. The findings revealed that nanoconjugates have the potential to enhance cellular sensitivity to radiation along with facilitating the detection of radiation-induced biochemical alterations within cancer cells., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Fereshteh Koosha reports financial support was provided by Shahid Beheshti University of Medical Sciences., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The present work focuses on the synthesis and properties of a novel multifunctional cerium(III) MOF, [Ce 2 (data) 3 (DMF) 4 ]·DMF (data 2- : 2,5-diaminoterephthalate), abbreviated as NH 2 -Ce-MUM-2. Its crystal structure reveals an intricate 3D 4,5-connected framework with a xah topology. This MOF features unique properties, such as open metal sites, presence of free amino groups, and high stability. Two main applications of NH 2 -Ce-MUM-2 were investigated: (i) as a heterogeneous catalyst in the CO 2 fixation into cyclic carbonates and (ii) as a material with third-order nonlinear optical activity. As a model reaction, the cycloaddition of CO 2 to propylene oxide to give the corresponding cyclic carbonate was explored under mild conditions, at the atmospheric pressure of carbon dioxide and in the absence of cocatalyst and added solvent. Various reaction parameters were investigated toward optimization and exploration of substrate scope, revealing up to 99% product yields of cyclic carbonate products. Besides, the structure of NH 2 -Ce-MUM-2 is highly stable, permitting its recyclability and reusability in further catalytic experiments. The significant contributions of free amino groups and open metal sites within this catalyst were particularly considered when proposing a potential mechanism for the reaction. Z -Scan measurements were used to evaluate the nonlinear optical (NLO) properties of NH 2 -Ce-MUM-2 at various laser intensities. A high two-photon absorption (TPA) under greater incident intensities shows that NH 2 -Ce-MUM-2 might be applicable in optical switching devices. Besides, the self-focusing effects of NH 2 -Ce-MUM-2 under various incident intensities were highlighted by the nonlinear index of refraction ( n 2 ). By reporting the synthesis and characterization of a novel MOF, along with its highly promising catalytic and NLO behavior, the current study introduces an additional example of multifunctional material into a growing family of metal-organic frameworks.

A new two-dimensional carbon allotrope named twin α-trigraphyne monolayer is introduced in the present study and compared with α-trigraphyne monolayer. The structural, mechanical, electronic, and optical characteristics of α-trigraphyne and twin α-trigraphyne sheets are studied by density functional theory. The cohesive energy, ab initio molecular dynamics simulations, and phonon dispersion confirm that these sheets are energetically favorable and thermodynamically stable at room temperature. Both α-trigraphyne and twin α-trigraphyne, due to their porous structures, are more easily deformable than graphene. Calculations of the electronic properties indicate that both of the considered sheets are metals. In addition, the optical properties are investigated for incident light with parallel and perpendicular polarizations. The optical behavior of the sheets is found to be strongly anisotropic. For light parallel to the sheets, high optical constants and strong optical absorption are observed. The combinations of structural, electronic, mechanical, and optical properties make α-trigraphyne and twin α-trigraphyne suitable candidates for use in photovoltaics and touchscreen applications.

For the advancement of laser technologies and optical engineering, various types of new inorganic and organic materials are emerging. Metal-organic frameworks (MOFs) reveal a promising use in nonlinear optics, given the presence of organic linkers, metal cluster nodes, and possible delocalization of π-electron systems. These properties can be further enhanced by the inclusion of solely inorganic materials such as polyoxometalates as prospective low-cost electron-acceptor species. In this study, a novel hybrid nanocomposite, namely, SiW 12 @NU-1000 composed of SiW 12 (H 4 SiW 12 O 40 ) and Zr-based MOF (NU-1000), was assembled, completely characterized, and thoroughly investigated in terms of its nonlinear optical (NLO) performance. The third-order NLO behavior of the developed system was assessed by Z -scan measurements using a 532 nm laser. The effect of two-photon absorption and self-focusing was significant in both NU-1000 and SiW 12 @NU-1000. Experimental studies suggested a much superior NLO performance of SiW 12 @NU-1000 if compared to that of NU-1000, which can be assigned to the charge-energy transfer between SiW 12 and NU-1000. Negligible light scattering, good stability, and facile postsynthetic fabrication method can promote the applicability of the SiW 12 @NU-1000 nanocomposite for various optoelectronic purposes. This research may thus open new horizons to improve and enhance the NLO performance of MOF-based materials through π-electron delocalization and compositing metal-organic networks with inorganic molecules as electron acceptors, paving the way for the generation of novel types of hybrid materials for prospective NLO applications.

We successfully synthesized VS 2 -NiS 2 hybrid nanostructures via a one-pot hydrothermal technique. Microstructural characterizations were carried out by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The optical indexes such as n , k , and ε were assessed based on the reflectance spectra data and Kramers-Kronig method. By adding varying amounts of the NiS 2 phase in the hybrid nanostructure, the morphology of the hybrid nanostructures is altered to produce microflowers, nanoflakes, and nanoflowers. These changes affect the nonlinear optical properties. The third order nonlinear optical parameters ( n 2 , β ) were analyzed via a simple and accurate Z-scan technique using different laser powers. The two-photon absorption phenomenon has a significant enhancement effect on the nonlinear absorption process, but the nonlinear refractive behaviour of the different hybrid nanostructures changes from self-defocusing to self-focusing due to the alteration of the electronic state alignment and morphology. The magnitudes of n 2 and β are in the order of 10 -9 cm 2 W -1 and 10 -3 cm W -1 , respectively. The increasing of the density of states of electrons leads to the improvement of the nonlinear optical responses of the VS 2 -NiS 2 hybrid nanostructures in comparison with the pure VS 2 structure. This study demonstrates the great potential of this hybrid nanostructure for optical limiters and modulators as well as photonic devices., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new metal-organic framework (MOF), [Zn 4 (μ 4 -O)(μ 6 -L) 2 (H 2 O) 2 ] n · n DMF (ZSTU-10), was assembled from zinc(II) nitrate and N , N ', N ″-bis(4-carboxylate)trimesicamide linkers and fully characterized. Its crystal structure discloses an intricate two-fold 3D+3D interpenetrated MOF driven by the [Zn 4 (μ 4 -O)]-based tetragonal secondary building units and the C3-symmetric tris-amide-tricarboxylate linkers (μ 6 -L 3- ). Topological analysis of ZSTU-10 reveals two interpenetrated 3,6-connected nets with an rtl (rutile) topology. Z -Scan analysis at 532 nm was conducted to study a nonlinear optical (NLO) behavior of ZSTU-10. The nonlinear responses of ZSTU-10 were explored under various laser intensities, revealing notable third-order NLO properties in the visible region. A large two-photon absorption at lower incident intensities highlights the fact that ZSTU-10 can be applied in optical limiting devices as well as optical modulators. Moreover, a nonlinear refractive index ( n 2 ) is indicative of a self-defocusing behavior. This work thus expands a family of novel MOF materials with remarkable optical properties.