Value Of Magnetic Moment Research Articles

INFRARED SPECTRAL AND MAGNETIC PROPERTIES OF BASIC COPPER(II) NITRATE PRODUCED BY SLOW TITRATION METHOD

The main purposes for this work are to formulate and characterize the infrared (IR) and magnetic moment of the compounds resulted from the slow titration of copper(II) nitrate with sodium hydroxide and in the reverse procedures in an aqueous solution. The titration is carried out with various concentrations and at a constant temperature, ⁓ 19 oC, and monitored using pH meter with the rate of the titration⁓ 1 mL per minute. The corresponding data of change in mole ratio of Cu2+/OH- against pH reveals that the end point of the titration occurs at pH about 8, leading to stoichiometry formula, 3Cu(NO3)2.5Cu(OH)2, but Cu(NO3)2.5Cu(OH)2 in the reverse procedure (OH-/Cu2+). The pale blue for the former but deep blue compounds were isolated and then characterized IR spectroscopy and magnetic moment. Both compounds containing nitrate ion are evident from the corresponding IR spectra, and their magnetic moment values which were found in the range of 1.7-1.9 BM, are to be normal for copper(II) salt corresponding to one unpaired electron in the electronic configuration.

Magnetic properties of rare-earth zigzag chain systems RAgSe2 (R = Ho, Er, Tm, and Yb)

In an antiferromagnetic zigzag chain, competition between the nearest and next-nearest neighbor interactions could give rise to magnetic frustration. Magnetic semiconductors RAgSe2 (R = Ho, Er, Tm, and Yb) crystallize in the ErAgSe2-type orthorhombic structure, where the R ions form a zigzag chain along the orthorhombic a-axis. The magnetic susceptibility data for all the samples follow the Curie-Weiss law between 40 and 300 K. The values of the effective magnetic moment μ βα are close to those expected for the free R 3+ ions. Negative values of the paramagnetic Curie temperature θρ indicate antiferromagnetic interactions. For R = Ho and Tm, the specific heat C(T) data exhibit no anomaly down to 0.4 K, which is ascribed to the nonmagnetic singlet ground states under the crystalline electric fields. On the other hand, for R = Er, C(T) shows peaks at T 1 = 1.3 K and T2 = 0.9 K, indicating successive antiferromagnetic transitions. For R = Yb, C(T) shows a lambda-type anomaly at T m = 1.8 K. The magnetic entropy at T m is only 30% of Rln2 expected for the ground state doublet, suggesting magnetic fluctuations above T m.

The Temperature Effect on the Physical Properties of CoMnSb Half-Heusler Ferromagnetic: Density Functional Theory and Monte Carlo Simulation

In this work, we have studied the effect of temperature on structural, magnetic, electronic, elastic, thermodynamical properties of half-Heusler CoMnSb by using density functional theory (DFT) and Monte Carlo simulations. The semi-classical Boltzmann transport theory in combination with DFT is implemented to evaluate the thermoelectric (TE) properties. The obtained ground state properties show that CoMnSb has a half metallic character with a magnetic moment value of about 3μ B . Thermodynamical parameters have been studied using quasi-harmonic approximation (QHA) in the range of temperature 0–1000 K. The results of QHA show that the CoMnSb maintain their mechanical stability under temperature. The obtained results of TE properties show that CoMnSb exhibits a low lattice thermal conductivity and that ZT increases with temperature and reaches the maximum value of 0.098 at 1000K. The Monte Carlo simulation is used to investigate the magnetic properties of CoMnSb. Moreover, the transition temperature T C and the hysteresis cycle are calculated. These properties show that the CoMnSb half-Heusler is a good candidate for spintronic applications.

Synthesis, Characterization and Bio-Potential Activities of Co(II) and Ni(II) Complexes with O and N Donor Mixed Ligands

The synthesis and characterization of Co(II) and Ni(II) mixed ligand complexes are derived from isoniazid, 9-fluorenoneandoxalate. The metal complexes were characterized on the basis of elemental analysis, IR, UV-visible, CV, PXRD, and molar conductance analytical data, viz., all the metal complexes were suggested in an octahedral geometry, respectively. The mixed ligand complexes are formed in the 1:1:2:1 (M:L1:L2:L3) ratios, as found from the elemental analyses, and originate to have the formula [M(L1)(L2)2(L3)]. Where M = Co(II), Ni(II), L1 = isoniazid, L2 = 9-fluorenone, and L3 = oxalate. The molar conductance data reveals that the complexes are non-electrolytes. The cyclic voltammogram of the Co(II) complex revealed that the quasi-reversible single electron transfer process and Ni(II) complex corresponding to a one-electron transfer process were observed during controlled potential electrolysis. IR spectra show that the ligands are coordinated to the metal ions through N and O donor sites of isoniazid-N, 9-fluorenone-O and oxalate-O. Magnetic moment values and UV-visible spectra were used to infer the coordinating of the geometrics of these complexes found to be octahedral. The PXRD patterns suggest that all the complexes are crystalline phases. The metal chelates have been screened for antimicrobial, antioxidant and anti-inflammatory activities, and our findings have been reported, explained and compared with some known antibiotics.

Soft gluon fields and anomalous magnetic moment of muon

An impact of nonperturbatively treated soft gluon modes on the value of anomalous magnetic moment of muon a μ is studied within the mean-field approach to QCD vacuum and hadronization. It is shown that radial excitations of vector mesons strongly enhance contribution of hadronic vacuum polarization to a μ , doubling the contribution of one-meson processes compared to the result for ground state mesons. The mean field also strongly influences the hadronic light-by-light scattering contribution due to the Wilson line in quark propagators.

Preparation, spectral study and antimicrobial activity of binary Co(II) complexes derived from 2’-hydroxy chalcones

ABSTRACT. The present work comprises preparation, characterization, thermal behavior and growth inhibitory activity of some novel Co(II) complexes derived from substituted (E)-1-(1-hydroxy-4-iodonaphthalen-2-yl)-3-phenylprop-2-en-1-one (L1) and (E)-1-(4-bromo-1-hydroxynaphthalen-2-yl)-3-phenylprop-2-en-1-one (L2-L6). Newly synthesized metal-ligand complexes were structurally confirmed with suitable spectroscopic technique such as FT-IR, EPR, NMR (both 1H and 13C). XRD analysis for complex C1 confirmed the crystal system; tetragonal and space group; P 42/n: 2 with unit cell dimensions a, b = 13.3516 Å, c = 10.8009 Å; α, β, γ = 90o. The IR and EPR study demonstrated that interaction between metal ions and ligand occurs through carbonyl oxygen and hydroxyl oxygen. From the values of magnetic moment (μ) it was observed that synthesized complexes (C1-C6) are paramagnetic with three unpaired electrons contain one electron in t2g orbital and two electrons in eg orbitals. Further all these complexes have been evaluated in-vitro for their antimicrobial activity against the Gram positive bacteria Staphylococcus aureus, Gram negative bacteria Escherichia coli and the yeast Candida albicans. The complex C1 showed the significant antimicrobial activity, whereas the complexes C2, C4, C5 and C6 are moderately active against the tested pathogens. The antimicrobial data revealed that growth inhibitory activities of complexes were enhanced comparatively than its respective ligands. The enhanced antimicrobial activity is attributed to the presence of halogens (Br, Cl, I) and hydroxyl (OH) active substituents associated with the basic nucleus of complexes. Therefore, the present study helps to develop a new class of antimicrobial analogues.
 
 KEY WORDS: Metal complexes synthesis, 1,3-Diaryl-2-propene-1-one, Crystal structure, Thermal properties, Antimicrobial activity
 
 Bull. Chem. Soc. Ethiop. 2021, 35(3), 513-524.
 DOI: https://dx.doi.org/10.4314/bcse.v35i3.4

Effect of Doping on the Electronic Structure of the Earth's Lower Mantle Compounds: FeXO3 with X = C, Al, Si.

The effect of the mutual doping of C, Si, and Al atoms on the electronic structure and magnetic properties of FeXO3 (X = C, Al, Si) compounds, which are constituent compounds of the Earth’s lower mantle, was studied. In our first principles calculations, it was found that doping with carbon for both FeSiO3 and FeAlO3 leads to the transition of the compound from a half-metallic state to a metallic one. The values of the magnetic moments of Fe were obtained for pure and doped compounds. For the doped compounds, there is a tendency of the Fe magnetic moment to increase with the growth in the number of substituted ions in the case of replacing Si with C and Si for Al; on the contrary, in the case of replacing Al with C and Si, a decrease in the magnetic moment was revealed. For FeXO3 (X = C, Al, Si), the obtained magnetic moment values were found to be in a good agreement with the known experimental data.

Magnetic structure of the double perovskite La2NiIrO6 investigated using neutron diffraction

A polycrystalline sample of ${\mathrm{La}}_{2}{\mathrm{NiIrO}}_{6}$ has been synthesized and characterized using magnetization and neutron powder diffraction to explore the magnetic ground state. Three anomalies are evident in the bulk magnetization measurements at 28, 50, and 74 K, of which only the 74 K transition is associated with long-range ordering of ${\mathrm{Ni}}^{2+}$ and ${\mathrm{Ir}}^{4+}$ spins. The neutron thermodiffractogram recorded between 1.5 and 90 K and Rietveld refinements of the temperature difference data 1.5--90 K, 40--90 K, and 62--90 K confirm that both the Ni and Ir moments order at the same temperature below 74 K. No change in the magnetic peak intensities or new peaks have been found further below 50 and 28 K indicating that the spin structure remains the same down to 1.5 K. The magnetic propagation vector is $k=(\textonehalf{}, \textonehalf{}, 0)$ and the estimated magnetic moment values at 1.5 K are ${\ensuremath{\mu}}_{\mathrm{Ni}}=1.39(8){\ensuremath{\mu}}_{\mathrm{B}}$ and ${\ensuremath{\mu}}_{\mathrm{Ir}}=0.35(3){\ensuremath{\mu}}_{\mathrm{B}}$. Contrary to a recent publication by Ferreira et al. [Phys. Rev. Mater. 5, 064406 (2021)] on the same compound, the improved data quality allows now to ascertain the presence of an ordered moment on the iridium sites. The magnetic structure proposed by Ferreira et al. is discussed and it is shown that there are several magnetic structures compatible with the data but indistinguishable by neutron powder diffraction methods.

Synthesis and characterization studies of pure and Ni doped CuO nanoparticles by hydrothermal method

An efficient synthesis of Ni doped CuO nanoparticles were carried out by hydrothermal method. The prepared material was subjected to X-ray diffraction (XRD), the morphological characteristics of the prepared material system were studied by scanning electron microscope (SEM) technique. FTIR spectra have confirmed the establishment of CuO nanoparticles. Optical absorption spectra of prepared nanoparticles were measured using UV–vis spectroscopy and photoluminescence (PL) studies. A thorough examination of the frequency dependent dielectric constant reveals the unique impact of various polarizations. According to the magnetic experiments, the produced nanoparticles had a maximal magnetic moment value of 5.0 wt% for Ni doped CuO Nps. All the above analysis were studied the grain size were found and calculated for pure CuO, Ni incorporated CuO respectively.

DNA binding affinities, anti-oxidant, antimicrobial and molecular docking activities of Pd (II) complexes of chromone Schiff bases

Pd (II) complexes of the Schiff bases derived from 3-formyl chromones and 4-amino antipyrine were conventionally synthesized. The structural characterization of these novel Schiff base complexes was done by Mass spectrometry, elemental analysis, FT-IR, electronic and 1H-NMR spectral techniques. The metal to ligand ratio is found to be in 1:1 ratio based on analytical data. Magnetic moment values and electronic spectra assign a square planar geometry to the complexes. The intercalation between CT-DNA and Pd (II) complexes was investigated by using absorption, emission spectroscopy and viscometry, additionally supported by molecular docking studies. Investigation of the radical scavenging potency against DPPH radical was significant. These complexes showed antimicrobial activity against E.Coli & Staphylococcus aureus.

Highly Accurate Derivation of the Electron Magnetic Moment Anomaly From Spherical Geometry Using a Single Evaluation

The electron magnetic moment anomaly (ae), is normally derived from the fine structure constant using an intricate method requiring over 13,500 evaluations, which is accurate to 11dp. This paper advances the derivation using the fine structure constant and a spherical geometric model for the charge of the electron to reformulate the equation for ae. This highly accurate derivation is also based on the natural log eπ, and the zero-order spherical Bessel function. This determines a value for the electron magnetic moment anomaly accurate to 13 decimal places, which gives a result which is 2 orders of magnitude greater in accuracy than the conventional derivation. Thus, this derivation supersedes the accuracy of the conventional derivation using only a single evaluation.

Longitudinal remagnetization of uniaxial antiferromagnetic nanoparticles: the role of spontaneous magnetic moment.

A kinetic theory of magnetic response of uniaxial antiferromagnetic nanoparticles is presented. Within the developed framework, a particular case when an external field is applied strictly along the anisotropy axis is considered in detail. Analysis of the relaxation spectrum of an antiferromagnetic particle with a spontaneous magnetic moment is performed. It is shown that in a wide frequency range the magnetic response of such particle is determined entirely by the relaxation mode with the longest time. An analytical expression for this time that explicitly contains a value of the decompensation magnetic moment is derived. Also, simple formulae for both static and dynamic longitudinal magnetic susceptibility of an antiferromagnetic nanoparticle are obtained. According to them, longitudinal susceptibility grows quadratically with the value of the spontaneous magnetic moment. Besides, if the latter is not zero, the change of the static susceptibility with temperature turns out to be non-monotonic. The influence of the spontaneous magnetic moment of the particle on the magnetization curves in strong fields is analysed using both energy approach and kinetic theory. The calculated dependences of the dynamic coercivity on the amplitude and variation rate of the applied field are qualitatively compared with experimental data. This article is part of the theme issue 'Transport phenomena in complex systems (part 2)'.

Synthesis, Spectroscopy of New Lanthanide Complexes with Schiff Base Derived From (4-Antipyrinecarboxaldehyde with Ethylene Di-Amine) and Study the Bioactivity

The study involved preparing a new compound by combining Schiff bases generated from compounds for antipyrine, including lanthanide ions (lanthanum, neodymium, erbium, gadolinium, and dysprosium). The preparation of the ligand from condensation reactions (4-antipyrinecarboxaldehyde with ethylene di-amine) at room temperature, and was characterization using spectroscopic and analytical studies ( FT-IR, UV-visible spectra, 1H-NMR, mass spectrometry, (C.H.N.O), thermogravimetric analysis (TGA), in addition to the magnetic susceptibility and conductivity measurement of the synthesis complexes, among the results we obtained from the tests, we showed that the ligand behaves with the (triple Valence) lanthanide ions, the multidentate behavior through two oxygen atoms of the carbonyl group and two nitrogen atoms of the azomethine group with all the prepared complexes in a molar ratio (1:1). The participation of six groups of bidentate nitrate in the coordination and indicating that their complexes have values of magnetic moment and paramagnetic character and, based on the results of those measurements, the geometrical shape of the complexes was proposed. The biological activity of the prepared complexes was studied using the antibacterial activity, as the results of its effectiveness showed the direction of the bacteria used (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Klebsiella pneumoniae) at the concentration of 1×10-3M

Antimicrobial, Cytotoxicity and Molecular Docking Study of New Quinoline Schiff Base and its Metal(II) Complexes

A new quinoline Schiff base ligand was synthesized by the reaction of 2-hydroxy-7-methylquinolin- 3-carbaldehyde and 4-methylbenzene sulfonohydrazide. Synthesized Schiff base further utilized for the formation of stable metal complexes with Cu(II), Ni(II), Co(II) and Cd(II) metal salts and characterized by different spectroscopic techniques i.e. 1H NMR, 13C NMR, FT-IR, UV-visible, ESR, MASS and TGA. The low molar conductance values indicate that synthesized metal(II) complexes were non-electrolytes. The magnetic moment value indicates that Cu(II), Ni(II) and Co(II) complexes were paramagnetic. Further, these compounds were screened for inhibition activity against four bacterial strains, three fungal strains and cytotoxicity against the A-549 and MCF-7 cell lines by using the MTT method. Among the synthesized complexes, metal complexes exhibited excellent anticancer activity against the human lung cancer cell line (A-549). Schiff base and its Cd(II) complex showed good antibacterial activity. Furthermore, molecular docking study shows the significant binding affinity of metal complexes with tubulin protein. Present study proposed that all the synthesized Schiff base metal(II) complexes have excellent biological activity and could be act as potential anticancer agents.

Electrical and magnetic properties of vanadium diselenide intercalated with chromium atoms

The study of the structural characteristics, electrical and magnetic properties was carried out on synthesized samples of vanadium diselenide intercalated with chromium atoms. Structural studies have shown a decrease in the symmetry of the crystal lattice from hexagonal to monoclinic with an increase in the concentration of intercalated atoms, caused by their ordering in the Van der Waals gap. In this case, a change in the resistive state occurs in samples of different compositions, which are characterized by opposite thermal coefficients of electrical resistance. The values of the effective magnetic moments of chromium ions in CrxVSe2 decrease in comparison with the spin characteristics with an increase in the chromium content and their change correlate with the concentration dependence of the parameter c of the unit cell. At low temperatures for compositions x>0.2, the compounds undergo a transition to the state of a spin glass with a critical temperature of up to 30 K. Keywords: vanadium diselenide, chromium, intercalation, electrical resistance, magnetic susceptibility, spin glass.

Effect of additional magnetic material Ni on structure and magnetic properties Eu2-xCexCu0.99Ni0.01O4+α-δ

Superconductors are materials with the unique characteristics when the temperature of the material is below its critical temperature, namely zero resistivity. There are many superconducting phenomena that need to be explained theoretically. One of them is the effect of addition of impurities on the physical properties of superconducting materials. In this study, the addition of 0.01 Ni magnetic impurities in the Eu2-xCexCuO4+α-δ material has been carried out to form the structure Eu2-xCexCu0.99Ni0.01O4+α-δ, in an under-doped area with a concentration of Ce (x) = 0.09 and 0.10. Material synthesis was carried out by the solid reaction method with prefire at 900 °C for 20 hours, sintering at 1,000 °C for 16 hours, and annealing at 900 °C for 10 hours by flowing argon (Ar) gas. The XRD measurements were carried out to investigate the crystal structure, while the magnetic properties were carried out by SQUID measurement at temperature of 2 K to 30 K. From the XRD measurements, it was found that the crystals formed had a tetragonal crystal structure T’ which was indicated by the appearance of two main peaks with Miller indices (103) and (110), lattice parameter a is 3,904 Å in both samples, lattice c is 11.8752 Å and 11.9738 Å for the concentrations of Ce (x) = 0.09 and 0.10. The volume of unit cells obtained were 181.0178 Å3 and 181.0244 Å3 with the bond distance between Cu-O of 1.9521 Å and 1.9523 Å. It was also obtained that the crystal size were 86.2604 nm and 91.6735 nm. From the SQUID measurement, it was found that the material Eu2-xCexCu0.99Ni0.01O4+α-δ has paramagnetic properties. The value of the effective magnetic moment was decreased by reducing the addition of Ni impurities of 0.0057 and 0.0051.

Электрические и магнитные свойства диселенида ванадия, интеркалированного атомами хрома

The study of the structural characteristics, electrical and magnetic properties was carried out on synthesized samples of vanadium diselenide intercalated with chromium atoms. Structural studies have shown a decrease in the symmetry of the crystal lattice from hexagonal to monoclinic with an increase in the concentration of intercalated atoms, caused by their ordering in the Van der Waals gap. In this case, a change in the resistive state occurs in samples of different compositions, which are characterized by opposite thermal coefficients of electrical resistance. The values of the effective magnetic moments of chromium ions in CrxVSe2 decrease in comparison with the spin characteristics with an increase in the chromium content and correlate with the concentration dependence of the parameter c of the unit cell. At low temperatures for compositions х> 0.2, the compounds undergo a transition to the state of a spin glass with a critical temperature of up to 30K.

A Review of Novel Instrumentation for Matrix Independent Ultratrace Analysis of Radionuclides using Collinear Resonance Ionisation Spectroscopy (CRIS)

The CRIS setup at CERN-ISOLDE is a high resolution laser spectroscopy experiment that is used to characterise exotic radionuclei with very low production rates. Acquisition of hyperfine spectra enable nuclear spins and precise values of nuclear magnetic dipole and electric quadrupole moments to be determined. The high sensitivity of the CRIS technique combined with the high selectivity make it an ideal candidate for quantitation of analytes in complex matrices. This review article reports on novel instrumentation under development at the University of Manchester, utilising the CRIS technique for targeted matrix independent ultra-trace analysis.

Feasibility study of tau-lepton anomalous magnetic moment measurements with ultra-peripheral collisions at the LHC

Precision measurements of the anomalous electromagnetic moment of leptons (al) may serve as one of the most promising directions in the search for new physics beyond the Standard Model. While the experimental value of the electron magnetic moment agrees with theoretical predictions with up to 11 significant digits, the muon magnetic moment shows deviations from the Standard Model value at the level of 4.2 sigma, indicating the possible occurrence of new physics effects. Although the aτ of the tau lepton with its heavy mass is expected to be ${{m_\tau ^2} \mathord{\left/ {\vphantom {{m_\tau ^2} {m_\mu ^2}}} \right. \kern-\nulldelimiterspace} {m_\mu ^2}} \approx 280$ times more sensitive to new physics effects than aμ, measurements of this quantity are rare. This is because the standard spin precession methods are not suitable for aτ measurements due to the very short tau lifetime. Ultra-peripheral collisions of heavy ions at the LHC may serve as an alternative tool to measure aτ. In ultra-peripheral collisions, hadronic interactions are strongly suppressed and long-distance electromagnetic processes dominate, providing an environment to study the electromagnetic properties of the tau lepton. The di-tau production process PbPb → PbPbγγ → PbPbττ contains two gamma-tau vertices and hence provides enhanced sensitivity to the anomalous magnetic and electric moments. In this contribution we discuss the feasibility of the aτ measurement in ultraperipheral collisions with the ALICE experiment and present projections of the sensitivity of the measurement for the upcoming heavy ion run in 2022 at LHC.

Emergence of Magnetic Transition in Cobalt Oxide Nanowires on Vicinal Pt Substrate

This letter is devoted to a theoretical study of the magnetic properties of supported pure and oxidized Co nanowires (NWs) on the vicinal surface of a Pt substrate. The main goal is to study the influence of oxygen on the magnetic properties of Co NWs. Transition metal atoms are magnetic, and oxygen effectively interacts with electromagnetic (EM) radiation in the optical range. Thus, by choosing the resonant frequency, it becomes possible to change the magnetic properties of oxide NW as a whole and switch the magnetic state of the wire by using an EM field. Our study has shown that Co oxide (CoO) NWs can exhibit magnetic properties in the ground state. Moreover, we observed the emergence of magnetic transition from a ferromagnetic to an antiferromagnetic state in a CoO NW under surface oxidation. We show that the magnetic properties of oxidized NWs depend strongly on the surface geometry. The study of the electronic structure of CoO NWs explains the reason for the formation of several magnetic states. The analysis of band structures of pure and oxidized Co NW shows that changes in magnetic states can be explained by the changes in band structure due to oxidation and that oxidation decreases the value of magnetic moments of the Co atoms in comparison to the pure NW. However, the values of these moments are still high.