PC Space Research Articles

Origin of the metamagnetic transitions in Y0.9Tb0.1Fe2D4.3

Deuterium insertion was used to tune the magnetic properties of Y0.9Tb0.1Fe2 Laves phase towards an itinerant electron metamagnetic (IEM) behavior. The latter is highly sensitive to chemical changes and external parameters. The structural and magnetic properties of Y0.9Tb0.1Fe2D4.3 were investigated using various neutron powder diffraction experiments in addition to magnetic measurements under steady and pulsed high magnetic fields up to 60 T. The deuteride crystallizes in a monoclinic structure (Pc space group) with 4.3 D atoms located in 18 tetrahedral interstitial sites. At zero field, it undergoes a ferrimagnetic-antiferromagnetic (FiM-AFM) transition at TM0 = 90 K, accompanied by an anisotropic magnetostriction and a negative cell volume expansion of 0.6 %. A second AFM-PM transition is observed at 146 K. Under pulsed magnetic field at 4.2 K, the deuteride displays a multistep magnetic behavior from ferrimagnetic to a ferromagnetic state, which can be attributed to a stepwise rotation of the Tb moments. The ZFC-FC magnetization curves at low fields exhibit an irreversibility below 90 K, followed by a sharp decrease in magnetization at the FM-AFM transition. Between 90 K and 130 K, the magnetization curves display an IEM behavior, with the transition field increasing linearly with temperature.

Laboratory Spectral Characterization of Ribbeck Aubrite: Meteorite Sample of Earth-impacting Near-Earth Asteroid 2024 BX1

Characterization of near-Earth objects (NEOs) is critical for Earth-impact hazard assessment. Particularly crucial to our physical understanding of NEOs are laboratory spectral measurements of meteorites as they are the best and most widely available analog materials, barring sample return missions. However, most meteorites do not have direct orbital links to specific asteroids, making it challenging to identify their source body in the NEO or main-belt asteroid populations. Near-Earth asteroid (NEA) 2024 BX1 was discovered on 2024 January 20 at 21:48 UTC from MPC code K88, impacting the Earth (west of Berlin, Germany) 165 minutes later. The incoming bolide was observed by multiple meteor cameras, which enabled successful reconstruction of its exo-atmospheric orbit and quick recovery. We present results from laboratory spectral characterization of the Ribbeck meteorite in the UV–mid-infrared wavelengths (0.2–14.2 μm) over seven grain size bins (<45 μm–slab). Our results suggest that Ribbeck has spectral properties consistent with enstatite achondrite (aubrite) meteorites. Our grain-size spectral analysis shows that albedo and spectral slope decrease as grain size increases. In addition, increasing grain size also shifts the taxonomic type in the Bus–DeMeo system from Xn to B types, suggesting the limitations of taxonomy in classifying small, regolith-free NEAs. We also present results of our comparison between Ribbeck data and spectra of E types in the main-belt and NEA populations. Principal component analysis of our Ribbeck samples shows variations parallel to the α line, which can be confused with space weathering in PC space.

Bioprocess monitoring applications of an innovative ATR-FTIR spectroscopy platform.

Pharmaceutical manufacturing is reliant upon bioprocessing approaches to generate the range of therapeutic products that are available today. The high cost of production, susceptibility to process failure, and requirement to achieve consistent, high-quality product means that process monitoring is paramount during manufacturing. Process analytic technologies (PAT) are key to ensuring high quality product is produced at all stages of development. Spectroscopy-based technologies are well suited as PAT approaches as they are non-destructive and require minimum sample preparation. This study explored the use of a novel attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy platform, which utilises disposable internal reflection elements (IREs), as a method of upstream bioprocess monitoring. The platform was used to characterise organism health and to quantify cellular metabolites in growth media using quantification models to predict glucose and lactic acid levels both singularly and combined. Separation of the healthy and nutrient deficient cells within PC space was clearly apparent, indicating this technique could be used to characterise these classes. For the metabolite quantification, the binary models yielded R 2 values of 0.969 for glucose, 0.976 for lactic acid. When quantifying the metabolites in tandem using a multi-output partial least squares model, the corresponding R 2 value was 0.980. This initial study highlights the suitability of the platform for bioprocess monitoring and paves the way for future in-line developments.

The Initial Mass Function Based on the Full-sky 20 pc Census of ∼3600 Stars and Brown Dwarfs

A complete accounting of nearby objects—from the highest-mass white dwarf progenitors down to low-mass brown dwarfs—is now possible, thanks to an almost complete set of trigonometric parallax determinations from Gaia, ground-based surveys, and Spitzer follow-up. We create a census of objects within a Sun-centered sphere of 20 pc radius and check published literature to decompose each binary or higher-order system into its separate components. The result is a volume-limited census of ∼3600 individual star formation products useful in measuring the initial mass function across the stellar (<8M ⊙) and substellar (≳5M Jup) regimes. Comparing our resulting initial mass function to previous measurements shows good agreement above 0.8M ⊙ and a divergence at lower masses. Our 20 pc space densities are best fit with a quadripartite power law, ξ(M)=dN/dM∝M−α , with long-established values of α = 2.3 at high masses (0.55 < M < 8.00M ⊙), and α = 1.3 at intermediate masses (0.22 < M < 0.55M ⊙), but at lower masses, we find α = 0.25 for 0.05 < M < 0.22M ⊙, and α = 0.6 for 0.01 < M < 0.05M ⊙. This implies that the rate of production as a function of decreasing mass diminishes in the low-mass star/high-mass brown dwarf regime before increasing again in the low-mass brown dwarf regime. Correcting for completeness, we find a star to brown dwarf number ratio of, currently, 4:1, and an average mass per object of 0.41 M ⊙.

Polar Organic Charge-Transfer Complex of the Asymmetrical Component for Flexible Piezoelectric Energy Harvesting and Self-Powered Wearable Sensors.

Organic piezomaterials have attracted much attention because of their easy processing, lightweight, and mechanic flexibility properties. Developing new smart organic piezomaterials is highly required for new-generation electronic applications. Here, we found a novel organic piezomaterial of organic charge-transfer complex (CTC) consisting of dibenzcarbazole analogue (DBCz) and tetracyanoquinodimethane (TCNQ) in the molecular-level heterojunction stacking mode. The DBCz-TCNQ complex exhibited ferroelectric properties (the saturated polarization of ∼1.23 μC/cm2) at room temperature with a low coercive field. The noncentrosymmetric alignment (Pc space group) led to a spontaneous polarization of this architecture and thus was the origin of the piezoelectric behavior. Lateral piezoelectric nanogenerators (PENGs) based on the thermal evaporated CTC thin-film exhibited significant energy conversion behavior under mechanical agitation with a calculated piezoelectric coefficient (d31) of ∼33 pC/N. Furthermore, such a binary CTC thin-film constructed single-electrode PENG could show steady-state sensing performance to external stimuli as this flexible wearable device precisely detected physiological signals (e.g., finger bending, blink movement, carotid artery, etc.) with a self-powered supply. This work provides that the polar CTCs can act as efficient piezomaterials for flexible energy harvesting, conversion, and wearable sensing devices with a self-powered supply, enabling great potential in healthcare, motion detection, human-machine interfaces, etc.

Synthesis and characterization of a new chalcone-based nonlinear optical crystal: BBC

A new chalcone-based nonlinear optical crystal BBC (C22H17BrO2) using long π-conjugated and halogen substituent, as a potential alternative to develop organic crystals, are reported. BBC was designed and synthesized by replacing benzyloxy and -Br groups on both sides of molecular framework. Flaky yellowish BBC single crystal with size of 5 × 5 × 1 mm3 was grown by solution evaporation method. BBC crystal crystallizes in the monoclinic system, Pc (NO. 7) space group, with noncentrosymmetric structure. In the BBC molecule, benzyl oxide acts as donor (D) and Br and carbonyl group act as acceptor (A), forming D - π - A - π - A structure with electron gradient. The introduction of Br group, which contributes to strong halogen bond formation, lead to the “head-to-tail” arrangement. Remarkably, BBC exhibits strong second harmonic generation (SHG) intensity (14 × KDP and 2.2 × Urea), wide transmission range (600-1600 nm, >60%), high optical energy gap (Eg=2.85 eV) and high thermal stability (Tm=106 °C). In addition, to investigate the relationships between the structure and physical properties, the electronic structure and optical properties of BBC crystal were theoretically calculated. This work not only provides a newly chalcone-based NLO crystal, but also presents a feasible molecular design approach by introducing long π-conjugated and halogen substituents.

Investigation on Optical, Electrical, Third Harmonic Generation and Hirshfeld Analysis Characteristics of Novel Organic 3‐Amino‐1H‐1,2,4‐Triazole 3,5‐Dinitrobenzoic Acid Monohydrate (3ATDM) Crystal for Nonlinear Optical (NLO) Applications

AbstractThe organic 3‐amino‐1H‐1,2,4‐triazole 3,5‐dinitrobenzoic acid monohydrate (C9 H10 N6 O7) (H2O) (3ATDM) single crystal is synthesized and grown using the slow evaporation solution technique (SEST), for the first time. Single crystal X‐ray diffraction (SXRD) analysis indicated that the 3ATDM crystal has the characteristics of the noncentrosymmetric Pc space group of the monoclinic crystal system. The crystal have good optical characteristics as observed using UV‐visible‐near infrared (NIR) analysis; the transmittance wavelength region is in the range of 200–1000 nm. Sharp emission peaks are observed in the photoluminescence spectrum; this is indicative of ultraviolet (UV) emission. Thermogravimetric and differential thermal analysis (TG‐DTA) is used to evaluate the thermal behavior. The 3ATDM crystal is thermally stable up to 207 °C; the first endothermic peak appeared at 150 °C. The dielectric loss (tan δ) and dielectric constant (ε') are measured as a function of frequency. Vickers microhardness analysis is used to characterize the mechanical strength of the 3ATDM crystal. The third‐order nonlinear optical properties such as absorption coefficient (β), refractive index (n2), and susceptibility (χ (3)) are evaluated through the Z‐scan technique at 532 nm, using a continuous wave (CW) solid‐state laser.

New organic (Dye) Sensitized Solar Cells with ferric iron III oxide doped barium chromite (Fe2O3-BaCrO4)

A new organic Dye has been successfully synthesized by a slow evaporation method. A single crystal x-ray diffraction study confirms the crystal system and lattice parameters of E-2HM4N. Powder XRD and NMR data were used to determine the crystal structure. The crystal system is a monoclinic Pc space group. Thus, the PXRD analysis confirms the good crystallinity nature and purity. UV–Vis spectral analysis has been used to measure the optical absorption of E-2HM4N its confirmed by a semiconducting material and the band gap energy is 2.1 eV. The nano dimension morphology of the particle was confirmed by FESEM. The characterization is (I -V) relationships between Maximum Voltage (518 mV) and Maximum Current (1.6 mA) is calculated by efficiency 0.8%. According to a survey of the literature, binary metal oxide Fe2BaCrO7 with organic dye E-2HM4N is newly reported. A flexible DSSCs was successfully fabricated.

The choice of spectral similarity algorithms influences suspected soil sample provenance

Similarity algorithms are commonly used in soil forensic applications to help identify similar samples from an existing reference library as possible source locations of unknown target samples. These algorithms are well-suited to compare soil spectra. However, different similarity algorithms may lead to different clusters of similar samples, and thus different strengths of evidence in forensic investigations. To quantify this, we conducted a study to evaluate the influence of seven similarity algorithms on soil provenance, using as a sample set a soil spectral library consisting of 280 soil profiles from Anhui Province, China. This library includes three spatial scales of datasets: provincial (DSp), county (DSc) and field (DSf). A set of ten samples covering a wide range of spectra variations were selected from the DSf dataset as the “unknown” samples, with the remaining being used as the reference samples. This study aimed to: (1) evaluate how several commonly-used similarity algorithms, namely Euclidean distance (ED), Mahalanobis distance (MD), Spectral angle mapper (SAM), and Spectral information divergence (SID), as well as variants of several of these measured in standardized principal component space computed from the spectra (ED_PCA, MD_PCA and SAM_PCA), influence the identification of the matched similar samples; (2) determine the overlap in sample selection between different similarity algorithms; (3) propose best practices for similarity algorithms applied to soil forensic analysis using spectroscopy. The use of different similarity algorithms did influence the selection of most similar samples. The similarity algorithms calculated in PC space (ED_PCA, MD_PCA and SAM_PCA) performed slightly better than their counterparts calculated in spectral space. Due to the availability of a detailed spectral library, regardless of the different similarity algorithms used, the matched most similar samples were all located close to the unknowns, mostly within 3 km, with one exception. That is, the varied choices of different similarity algorithms hardly influenced the conclusion of soil provenance in this case. In general, MD_PCA, SAM and ED were the best similarity algorithms overall. However, since there was no single best algorithms for all cases, we recommend the joint use of MD_PCA, SAM and ED as an ensemble. Indications of possible sample provenance from these similarity measured can be useful evidence to complement evidence from other methods in a forensic investigation.

DISCREPANCY MODELING FOR MODEL CALIBRATION WITH MULTIVARIATE OUTPUT

This paper explores the application of the Kennedy and O'Hagan (KOH) Bayesian framework to the calibration of physics models with multivariate outputs by formulating the problem in a dimension-reduced subspace. The approach in the KOH framework is to calibrate the physics model parameters simultaneously to the parameters of an additive discrepancy (model error) function. It is a known issue that such discrepancy functions may result in non-identifiability between the model parameters and discrepancy function parameters. Three main approaches to avoid this problem have been considered in the literature: (i) careful definition of the parameter priors based on extensive knowledge of the problem physics, (ii) separating the calibration process into more than a single step (referred to as a modular or sequential solution), or (iii) choosing functions that are less flexible than a Gaussian process (GP). By transformation of the problem into a dimension-reduced principal components (PC) space &amp;#91;using PC analysis (PCA)&amp;#93;, we explore a fourth approach to this problem. Advantages are dimension reduction of the calibration problem due to fewer outputs, simplified discrepancy functions and priors, and feasibility for the simultaneous solution approach. The additive discrepancy method is limited in the case of future predictions with the model; thus, we instead suggest how the results may be used for model diagnostic purposes. The methods are demonstrated on a simple numerical example and gas turbine engine heat transfer model.

Assessment of Vecuronium Quality Using Near-Infrared Spectrometry.

This study employed Fourier Transform near-infrared spectrometry to assess the quality of vecuronium bromide, a neuromuscular blocking agent. Spectral data from two lots of vecuronium were collected and analyzed using the BEST metric, principal component analysis (PCA) and other statistical techniques. The results showed that there was variability between the two lots and within each lot. Several outliers in the spectral data suggested potential differences in the chemical composition or sample condition of the vials. The outliers were identified and their spectral features were examined. A total of eight unique outliers were found in the PC space from PCs 1 to 9, so 22% of the total vials were outliers. The study findings suggest that the manufacturing process of vecuronium bromide may have been operating outside of a state of process control. Further investigation is needed to determine the source of these variations and their impact on the safety and efficacy of the drug product.

Optimizing column-to-column retention time alignment in high-speed gas chromatography by combining retention time locking and correlation optimized warping

We examine and then optimize alignment of chromatograms collected on nominally identical columns using retention time locking (RTL), an instrumental alignment tool, and software-based alignment using correlation optimized warping (COW). For this purpose, three samples are constructed by spiking two sets of analytes into a base test mixture. The three samples are analyzed by high-speed gas chromatography with four nominally identical columns and identical separation conditions. The data is first analyzed without alignment, then using COW alone, then RTL alone, and finally with RTL followed by COW to correct the severe column-to-column misalignment. Principal component analysis (PCA) is used to investigate how well each alignment method clustered the chromatograms into the three sample classes via a scores plot without being compromised by the specific column(s) used. The degree-of-class separation (DCS) is used as a classification metric, measured as the Euclidian distance between the centroids of two clusters in PC space in the scores plot, normalized by their pooled variance. With no alignment, the average DCS between sample classes (DCSsam) was 3.0, while the average DCS between the four nominally identical columns, i.e., column classes (DCScol) was 76.1 (ideally the DCScol should be 0), indicating the chromatograms were initially classified by the columns used. Using either COW or RTL alone also produced unsatisfactory results, with COW alone incorrectly aligning many peaks, leading to a DCSsam of only 1.9 and DCScol of 1.7, while RTL alone provided a DCSsam of 4.7 and DCScol of 4.2. Finally, using RTL followed by COW alignment, DCSsam increased to 32.5, indicating successful classification by chemical differences between sample classes, while the DCScol decreased to 0.4, indicating virtually no classification due to column-to-column differences, as desired. Thus, RTL provided a “first-order” correction of the initial retention mismatch observed for the nominally identical columns, while additional alignment via COW was required to optimize sample classification by PCA.

A new approach to chromeno[4,3-b]pyridine: Synthesis, X-ray, spectral investigations, hirshfeld surface analysis, and computational studies

The structural motif of chromeno[4,3-b]pyridine can be found in a wide variety of pharmaceuticals and bioactive compounds. In this study, we have synthesized 2-(4,5-di-p-tolyl-5H-chromeno[4,3-b]pyridin-2-yl)phenol utilizing microwave radiation as an eco-friendly procedure upon the reaction of 2′-hydroxy-4-methylchalcone with urea under basic conditions. The obtained compound was confirmed using spectroscopic analysis, including FT-IR, UV–visible, 1H NMR, 13C NMR, mass spectroscopy, and X-ray crystallography. Moreover, the crystal structure of the chromeno[4,3-b]pyridine derivative exhibited a monoclinic system and Pc space group. Theoretical calculations were used as a comparative study of the X-ray crystal structure of this chromenopyridine using the B3LYP and HF/6–311(G) basis set and experimental bond length and angles, which showed that the HF method was more accurate than the DFT method. Furthermore, the calculated NMR, FT-IR, and UV–vis spectra obtained for the chromeno[4,3-b]pyridine derivative were in good agreement with the experimental data. In addition, the Mulliken charges, MEP, and HOMO-LUMO energy gap of this chromenopyridine were theoretically calculated. The Hirshfeld surface analysis showed the most important interactions formed between the molecules in the crystal.

Existence of periodic solutions of second-order nonlinear random impulsive differential equations via topological degree theory

In this paper, we investigate the existence of periodic solutions for a class of second order nonlinear random impulse differential equations. By extending the definitions of continuous function bound set, curvature bound set and Nagumo set in topological degree to PC space, and defining the appropriate operators and conditions, using the theory of topological degree and coincidence degree, we prove that the solution must be bounded if it exists and find the boundary value. Finally, we define appropriate Nagumo set and autonomous curvature bound set, and obtain the existence of periodic solutions of equations and simultaneous equations by using Mawhin’s continuity theorem.

Polymeric Terbium(III) Squarate Hydrate as a Luminescent Magnet

Polymeric terbium(III) squarate hydrate [{Tb2(C4O4)3(H2O)8}n] was prepared from TbCl3 or Tb2O3 and squaric acid. The crystal structure was determined in a monoclinic Pc space group, and the whole molecular arrangement gives a sandwiched two-dimensional structure. The coordination polyhedra are described as a square antiprism. The solid complex emits green light under UV irradiation at room temperature with the quantum yield of 25%. Although Tb3+ is a non-Kramers ion, the alternating-current magnetic susceptibility showed frequency dependence in a 2000-Oe DC field, and the effective energy barrier for magnetization reorientation was 33(2) K. Thus, [{Tb2(C4O4)3(H2O)8}n] displayed functions of a potential luminescent magnet.

Exploring the Role of Crystal Water in Potassium Manganese Hexacyanoferrate as a Cathode Material for Potassium-Ion Batteries

The Prussian Blue analogue K2−δMn[Fe(CN)6]1−ɣ∙nH2O is regarded as a key candidate for potassium-ion battery positive electrode materials due to its high specific capacity and redox potential, easy scalability, and low cost. However, various intrinsic defects, such as water in the crystal lattice, can drastically affect electrochemical performance. In this work, we varied the water content in K2−δMn[Fe(CN)6]1−ɣ∙nH2O by using a vacuum/air drying procedure and investigated its effect on the crystal structure, chemical composition and electrochemical properties. The crystal structure of K2−δMn[Fe(CN)6]1−ɣ∙nH2O was, for the first time, Rietveld-refined, based on neutron powder diffraction data at 10 and 300 K, suggesting a new structural model with the Pc space group in accordance with Mössbauer spectroscopy. The chemical composition was characterized by thermogravimetric analysis combined with mass spectroscopy, scanning transmission electron microscopy microanalysis and infrared spectroscopy. Nanosized cathode materials delivered electrochemical specific capacities of 130–134 mAh g−1 at 30 mA g−1 (C/5) in the 2.5–4.5 V (vs. K+/K) potential range. Diffusion coefficients determined by potentiostatic intermittent titration in a three-electrode cell reached 10−13 cm2 s−1 after full potassium extraction. It was shown that drying triggers no significant changes in crystal structure, iron oxidation state or electrochemical performance, though the water level clearly decreased from the pristine to air- and vacuum-dried samples.

Large-scale inference of population structure in presence of missingness using PCA.

Principal component analysis (PCA) is a commonly used tool in genetics to capture and visualize population structure. Due to technological advances in sequencing, such as the widely used non-invasive prenatal test, massive datasets of ultra-low coverage sequencing are being generated. These datasets are characterized by having a large amount of missing genotype information. We present EMU, a method for inferring population structure in the presence of rampant non-random missingness. We show through simulations that several commonly used PCA methods cannot handle missing data arisen from various sources, which leads to biased results as individuals are projected into the PC space based on their amount of missingness. In terms of accuracy, EMU outperforms an existing method that also accommodates missingness while being competitively fast. We further tested EMU on around 100K individuals of the Phase 1 dataset of the Chinese Millionome Project, that were shallowly sequenced to around 0.08×. From this data we are able to capture the population structure of the Han Chinese and to reproduce previous analysis in a matter of CPU hours instead of CPU years. EMU's capability to accurately infer population structure in the presence of missingness will be of increasing importance with the rising number of large-scale genetic datasets. EMU is written in Python and is freely available at https://github.com/rosemeis/emu. Supplementary data are available at Bioinformatics online.

UV Spectroscopic Determination of Aloin in Aloe vera (A. vera) Samples Based on Chemometric Data Processing

A simple method was developed for determining aloin in A. vera samples by UV–visible spectroscopy with the study of the results of measurements by principal component analysis (PCA), which showed the separation of samples in the PC space depending on their manufacturer. The spectra of model binary (aloin–malic acid) and ternary (aloin–malic acid–citric acid) systems and the spectra of A. vera samples were decomposed using the mutual information least dependent component analysis (MILCA) algorithm based on the minimization of numerical values of mutual information. A good correlation is observed for model mixtures between the predicted and actual concentrations of aloin in the samples under study (n = 3, r = 0.986). The spectra of the model systems, that is, A. vera samples with a known concentration of aloin, and the spectra of A. vera samples artificially contaminated relative to the initial samples were used as calibration systems for the decomposition of the spectra of A. vera samples by independent component analysis. It was demonstrated that UV spectroscopy in combination with corresponding chemometric data processing enables the quantitative determination of aloin in plant samples of A. vera.

A potent synthesis and supramolecular synthon hierarchy percipience of (E)-Nʹ-(Napthalen-1-yl-methylene)-benzenesulfonohydrazide and 1-Napthaldehyde: A combined experimental and DFT studies

An adduct of (E)-Nʹ-(Napthalen-1-yl-methylene)-benzenesulfonohydrazide (NMBSH) and 1-naphthaldehyde (NAH) was synthesized using an uncomplicated condensation procedure from the NAH and benzenesulfonylhydrazine (BSH) in a good yield (71.0%) and this was crystallized in EtOH. The adduct compound was characterized using spectroscopic techniques such as 1H NMR, 13C NMR, FT-IR and UV–Vis. Structure of adduct was established by using a single crystal X-ray diffraction method (SC-XRDM). The crystallographic parameters are a = 11.87(2)Å, b = 6.75(8)Å and c = 15.87(2)Å, β = 109.62(2)° and it was resolved in monoclinic crystal system and Pc space group. The molecules undergo hydrogen bonding interaction and π-π interaction in the crystal structure of compound. In order to understand the structural and electronic properties, computational calculations of NMBSH and NAH were carried out. All computational based calculations were performed using the DFT at B3LYP (Becke, 3 parameters, Lee-Yang-Parr) theory with 6-31+G (d,p) basis set. Natural bond orbitals (NBOs) analysis was computed at B3LYP/6-311+G (d,p) method. UV-VIS analysis was conducted by TD-DFT/B3LYP/6-31+G (d,p) level. A good agreement was obtained between the experimental and the computational structural data of NMBSH and NAH. The second order perturbation energies have been obtained by NBO analysis, confirmed interactions and strengthen in the intriguing architectures of NMBSH and NAH. With the help of DFT approach, HOMO-LUMO energies were figured out to obtain electronic insights into the NMBSH and NAH. Moreover, information regarding local as well as global chemical activity, nucleophilic and electrophilic nature of NMBSH and NAH has been obtained. Moreover, an excellent agreement was found between experimental and computational UV-VIS findings. The obtained NLO results indicated that our adduct as NMBSH and NAH displayed stronger response than reference molecule. It could be concluded that this study might be helpful for NLO materials.

Origin of the metamagnetic transitions in Y1−xErxFe2(H,D)4.2 compounds

The structural and magnetic properties of Y1−xErxFe2 intermetallic compounds and their hydrides and deuterides Y1−xErxFe2H(D)4.2 have been investigated using X-ray diffraction and magnetic measurements under static and pulsed magnetic field up to 60 T. The intermetallics crystallize in the C15 cubic structure (Fd-3m space group), whereas corresponding hydrides and deuterides crystallize in a monoclinic structure (Pc space group). All compounds display a linear decrease of the unit cell volume versus Er concentration; the hydrides have a 0.8% larger cell volume compared to the deuterides with same Er content. They are ferrimagnetic at low field and temperature with a compensation point at x = 0.33 for the intermetallics and x = 0.57 for the hydrides and deuterides. A sharp first order ferromagnetic-antiferromagnetic (FM-AFM) transition is observed upon heating at TFM−AFM for both hydrides and deuterides. These compounds show two different types of field induced transitions, which have different physical origin. At low temperature (T < 50 K), a forced ferri-ferromagnetic metamagnetic transition with Btrans1 ≈ 8 T, related to the change of the Er moments orientation from antiparallel to parallel Fe moment, is observed. Btrans1 is not sensitive to Er concentration, temperature and isotope effect. A second metamagnetic transition resulting from antiferromagnetic to ferrimagnetic state is also observed. The transition field Btrans2 increases linearly versus temperature and relates to the itinerant electron metamagnetic behavior of the Fe sublattice. An onset temperature TM0 is obtained by extrapolating TFM−AFM (B) at zero field. TM0 decreases linearly versus the Er content and is 45 ± 5 K higher for the hydrides compared to the corresponding deuteride. The evolution of TM0 versus cell volume shows that it cannot be attributed exclusively to a pure volume effect and that electronic effects should also be considered.