Antiferromagnetic Behavior Research Articles

Synthesis and Characterisation of Vanadium(III) Fluorides α-BaVF5 and BaV(F,OH)5 with an S = 1 Spin Chain Structure

Two new vanadium(III) fluorides, α-BaVF5 and BaV(F,OH)5, were hydrothermally synthesised. The crystal structures of both α-BaVF5 and BaV(F,OH)5 contain chain structures consisting of corner-sharing VIIIF6 or VIII(F,OH)6 octahedra. A monomeric cis-chain structure is found in α-BaVF5, in contrast to the helical-chain structure in BaV(F,OH)5. Although predominantly antiferromagnetic interactions are present in these tilted compounds at high temperatures, the strength of the exchange interaction is greater in α-BaVF5 due to the high Curie−Weiss temperature of θCW = -66.0(1)K. Furthermore, magnetic measurements revealed that α-BaVF5 exhibits a canted antiferromagnetic ground state, while BaV(F,OH)5 displays antiferromagnetic behaviour at low temperatures.

Radiation driven synthesis of MnSe nanoparticles with dual luminescence and magnetic characteristics and its role in photocatalytic reactions

Many biomedical applications can greatly benefit from the combination of photoluminescence and magnetic properties of non-toxic manganese-based nanomaterials and thus, it demands for synthesizing such materials in an aqueous environment. The present work reports aqueous synthesis of starch-capped manganese selenide (MnSe) nanoparticles (NPs) through a steady-state gamma irradiation route under ambient pressure and room temperature. As radiolysis is considered as the cleanest method among available chemical approaches, we preferred to employ this technique and endeavored to establish optimal conditions of such synthesis. The as-produced MnSe nanocrystals demonstrated strong photoluminescence with a quantum yield of ca. 32% and co-existence of paramagnetic with antiferromagnetic behavior. To look into possible light-induced reactions with aromatic molecules, the effectiveness of synthesized particles on photo-induced degradation of dyes of similar structure was investigated. The proposed strategy may pave the way for synthesizing magneto-fluorescent nanoparticles in aqueous medium, which may find immense scope in nano-photonics and nano-biotechnology including biological assays, labelling and imaging.

Crystal structure, Chemical Bonding, and Magnetism of α-Fe6Ga5: How Local Interactions Shape the Structure and Properties of Intermetallic Compounds.

α-Fe6Ga5 was synthesized from the elements as a polycrystalline powder. Its crystal structure was redetermined by high-resolution powder X-ray diffraction, which showed a complex monoclinic structure of the Fe6Ge5 type. The determined lattice parameters (a = 10.08380(6) Å, b = 7.97071(5) Å, c = 7.70489(5) Å, and β = 108.3062(2)°) differ notably from the previous reports. Despite possessing the same structure type as Fe6Ge5, α-Fe6Ga5 displays several distinctive features, such as short Ga-Ga bonds and distorted Fe layers. According to magnetization measurements, α-Fe6Ga5 is a soft ferromagnet with a high Curie temperature of 760 K, which is in stark contrast to the antiferromagnetic behavior of Fe6Ge5 reported in the literature. The electronic structure of α-Fe6Ga5 was studied theoretically using density functional theory-calculations, which showed the pronouncedly covalent character of the short Fe-Ga and Ga-Ga bonds. Similar calculations were performed for Fe6Ge5, which revealed stronger Fe-Ge interactions, which preclude the formation of short Ge-Ge bonds. In both cases, the theoretical calculations showed ferromagnetic instability, which leads to ferromagnetic ordering only in the case of α-Fe6Ga5, likely due to the different nature of Fe-Ga-Fe and Fe-Ge-Fe superexchange interactions.

Comprehensive Characterization of Bi1.34Fe0.66Nb1.34O6.35 Ceramics: Structural, Morphological, Electrical, and Magnetic Properties

Recent research in solid-state physics and materials engineering focuses on the development of new dielectric materials, with bismuth-based pyrochlores being already extensively applied in communications technology for their excellent dielectric properties and relatively low sintering temperatures. Herein, the structural, morphological, electrical, and magnetic properties of Bi1.34Fe0.66Nb1.34O6.35 ceramic, prepared by the sol–gel method and sintered at 500 °C, are investigated. The Rietveld refinement of the XRD pattern showed a cubic phase belonging to the space group Fd-3m and a crystallite size of 42 nm. Transmission electron microscopy further confirmed the crystallite size and the homogeneous distribution of Bi, Fe, Nb, and O elements, as evidenced by high-angle annular dark field imaging and STEM-EDX mapping. The morphology of the sample, assessed by scanning electron microscopy, is characterized by submicron-sized spherical particles. Dielectric spectroscopic studies revealed that the dielectric properties, strongly influenced by frequency and temperature, indicate the material’s potential for energy storage due to lower dielectric loss compared to the dielectric constant. The observed relaxation phenomena, confirmed through variations in dielectric loss and loss tangent, highlight the influence of grain boundaries and temperature on electron hopping and charge carrier dynamics. Using SQUID magnetometry, we identified two distinct magnetic phases. The primary phase, corresponding to the Bi1.34Fe0.66Nb1.34O6.35 ceramic, exhibits an antiferromagnetic behavior below its Néel temperature at around 8.8 K. A secondary high-Curie temperature ferrimagnetic phase, likely vestigial maghemite and/or magnetite, was also detected, indicating an estimated fraction below 0.02 wt.%.

Antiferromagnetic Frustration Behavior with Face-Sharing CuAs4 Tetrahedrons in Conducting ACu6As3 (A = Li and Na).

New mixed-valence copper pnictides ACu6As3 (A = Li and Na) adopt a quasi-2D structure type, featuring alkalis and [Cu6As3]- slabs along the c-axis alternatively. The face-sharing connection between CuAs4 polyhedra leads to a higher valence state for the inside Cu ions than that of Cu ions with the other connectivity way. This is confirmed by X-ray photoemission spectroscopy results. The Cu2+ with near spin 1/2 located on bilayer triangular lattice is found to exhibit a peculiar hump in magnetic susceptibility along the c-axis and, most strikingly, nearly a constant at low temperatures from 1.8 K down to 0.4 K. Besides, high hole mobilities, 68.58 and 645.16 cm2 V-1 S-1, are observed in LiCu6As3 and NaCu6As3, respectively. These compounds provide a novel material system for researching the relationship among structure, valence state, and spin correlation in frustrated lattice.

Insights into effects of Fe doping on phase stability, martensitic transformation, and magnetic properties in Ni-Mn-Ti-Fe all-d-metal Heusler alloys

In this work, the effects of Fe doping on phase stability, martensitic transformation, and magnetic properties of Ni50Mn37.5-xTi12.5Fex (x = 3.125, 6.25, 9.375) all-d-metal Heusler alloys were systematically investigated by first-principles calculations. The results indicate a tendency for doped Fe atoms to aggregate within the Ni50Mn37.5-xTi12.5Fex alloys. As Fe concentration increases, a gradual reduction in both lattice constants and phase stability of austenite and martensite is observed. In the absence or presence of minimal Fe doping, both austenite and martensite exhibit antiferromagnetic behavior. However, at x = 9.375, a transition to a ferromagnetic state is observed in the austenite phase. This transition is attributed to the activation of the ferromagnetic coupling effect in the austenite phase induced by Fe doping in the Ni-Mn-Ti alloy. In contrast, the martensite phase maintains its antiferromagnetic characteristics throughout the doping range. A comprehensive analysis of the electronic structure elucidates the underlying physical mechanisms responsible for the martensitic transformation and magnetic property changes.

Enhanced magnetism derived from pore-edge spins in thin Fe3GeTe2 nanomeshes

The growth of two-dimensional van der Waals magnetic materials presents attractive opportunities for exploring new physical phenomena and valuable applications. Among these materials, Fe3GeTe2(FGT) exhibits a variety of remarkable properties and has garnered significant attention. Herein, we have for the first time created a nanomesh structure-a honeycomb-like array of hexagonal nanopores-with the zigzag pore-edge atomic structure on thin FGT flakes with and without oxidation of the pore edges. It is revealed that the magnitude of ferromagnetism (FM) significantly increases in both samples compared with bulk flakes without nanomeshes. Critical temperature annealing results in the formation of zigzag pore edges and interpore zigzag-edge nanoribbons. We unveil that the non-oxide (O) termination of the Fe dangling bonds on these zigzag edges enhances FM behavior, while O-termination suppresses this FM by introducing antiferromagnetic behavior through edge O-Fe coupling. FGT nanomeshes hold promise for the creation of strong FM and their effective application in magnetic and spintronic systems.

A Tetranuclear copper(II) Complex with a Pyridine‐2,6‐dicarboxamide Ligand: Structural and Magnetic Properties and In vitro Antiproliferative Activity Against Human Cancer Cells

AbstractA pentadentate diamide ligand, N,N′‐di(pyridine‐2‐yl)pyridine‐2,6‐dicarboxamide (L1H2) and its tetranuclear Cu(II) complex [Cu4(L1)2(μ3‐OH)2(H2O)3(ClO4)](ClO4) ⋅ H2O are reported. X‐ray crystal structure of the complex reveals that it has an open‐book type architecture. Two central copper atoms are connected to each other by two hydroxo bridges. Each of these two hydroxo bridges also connects the two central copper atoms to one of the two terminal copper atoms. Variable temperature susceptibility measurements show that χMT decreases with the temperature, indicating a strong antiferromagnetic behavior. With the help of DFT calculations the magnetic data was analyzed using the spin Hamiltonian H=−2 J1S3 ⋅ S4 −2 J2(S3 ⋅ S1+ S3 ⋅ S2+ S4 ⋅ S1+ S4 ⋅ S2)−2 J3S1 ⋅ S2 (where subscripts 1 and 2 refer to the terminal copper atoms and 3 and 4 refer to the central copper atoms). The best fit was obtained with 2 J1=−322 cm−1, 2 J2=+34.8 cm−1, 2 J3=−8.8 cm−1 and g=2.18, indicating a δ‐type interaction between terminal copper atoms. The complex proves to be an avid binder of ct‐DNA, with apparent binding constant (Kapp) value estimated as 1.536×107 M−1. In vitro experiments indicate that the Cu(II) complex reduced the proliferation of HCT116 cells among other cell lines. This reduction of cell proliferation may be attributed to the enhancement of intracellular ROS, along with modulation and disruption of cell cycle associated proteins. SKC conceptualized the project, arranged funding and involved in overall coordination among collaborators, analyzing the data, and writing the paper. AM was involved in doing the experimental work on synthesis of the compounds, carrying out analytical and spectroscopic measurements, collecting X‐ray crystallographic data and DNA binding experiments. MS, SM and KDS were involved in study of anticancer activities of the complex. SS helped in refining X‐ray structure of the complex. MC did the magnetic measurements and analysis whereas AF did the DFT calculations.

Crossover from Relativistic to Non-Relativistic Net Magnetization for MnTe Altermagnet Candidate

We experimentally study magnetization reversal curves for MnTe single crystals, which is the altermagnetic candidate. Above 85 K temperature, we confirm the antiferromagnetic behavior of magnetization M, which is known for α-MnTe. Below 85 K, we observe anomalous low-field magnetization behavior, which is accompanied by the sophisticated \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M(\\alpha )$$\\end{document} angle dependence with beating pattern as the interplay between \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M(\\alpha )$$\\end{document} maxima and minima: in low fields, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M(\\alpha )$$\\end{document} shows ferromagnetic-like 180° periodicity, while at high magnetic fields, the periodicity is changed to the 90° one. This angle dependence is the most striking result of our experiment, while it can not be expected for standard magnetic systems. In contrast, in altermagnets, symmetry allows ferromagnetic behavior only due to the spin–orbit coupling. Thus, we claim that our experiment shows the effect of weak spin–orbit coupling in MnTe, with crossover from relativistic to non-relativistic net magnetization, and, therefore, we experimentally confirm altermagnetism in MnTe.

Chiral Ca–Mn-frameworks with double helical chains and one-dimensional channels constructed from enantiomorphous lactate synthons

Under solvothermal synthetic condition, lactate derivatives (R)-5-(1- carboxyethoxy)isophthalic acid ((R)-H3CIA) and (S)-5-(1-carboxyethoxy)isophthalic acid ((S)–H3CIA) assembled with Ca(Ⅱ) and Mn(Ⅱ) ions to obtain enantiomers {[MnCa0.5((R)-CIA)(H2O)]·((CH3)2NH2CH3CO2)0.5(H2O)}n (HU21-R) and {[MnCa0.5((S)-CIA)(H2O)]·((CH3)2NH2CH3CO2)0.5(H2O)}n (HU21–S), respectively. Complexes HU21-R and HU21–S belong to orthorhombic crystal system with chiral space group I212121. Single crystal X-ray diffraction analysis revealed that all oxygen atoms of synthons (R)-CIA3- and (S)-CIA3- participated in the coordination with metal ions. Thus, semi-rigid (R)-CIA3- and (S)-CIA3- anions become rigid linkers in HU21-R and HU21–S. Fragments of (R)-CIA3- anion are connected by Ca(Ⅱ) ions to build right-handed double helical chains in HU21-R, while the enantiomeric left-handed double helixes are constructed by (S)-CIA3- fragments and Ca(Ⅱ) ions in HU21–S. Additionally, Mn(Ⅱ) centers and CIA3− anions resulted in a rare 4,4,4-connected net with point symbol of (42.62.82)3(42.64). Ca(Ⅱ) ions were further filed into Mn-CIA-framework to form a three dimensional structure with one dimensional channel. Moreover, magnetic test indicates that the framework has a canted antiferromagnetic behavior.

Temperature-dependent lattice dynamics study on phase stability, martensitic transformation mechanism, and vibrational entropy properties of B2-type Ni–Mn–Ti Heusler alloy

The all-d-metal Ni–Mn–Ti Heusler alloy with its good mechanical properties and colossal caloric effects has attracted significant attention for mechanocaloric refrigeration. However, the phase stability of the B2-type disordered structure at finite temperatures and the physical origin of large phase transformation entropy change in theoretical calculation remain unclear. In view of thermal and strongly anharmonic effects, we combined the first-principles and temperature dependent effective potential calculations to systematically study the phase stability, martensitic transformation mechanism, and vibrational entropy properties of B2 partial disordered structures for Ni8Mn5Ti3 and Ni8Mn6Ti2. Our results showed the austenitic structures of Ni8Mn5Ti3 and Ni8Mn6Ti2 both exhibit antiferromagnetic interaction behaviors at targeted temperatures, resolving the contradiction between previous calculations and experiments. By the analysis of phonon dispersion relations and Helmholtz free energies at low and high temperatures, we provided a deeper explanation for the underlying mechanism of martensitic transformation. Meanwhile, the phase transformation temperatures and vibrational entropy changes were accurately predicted compared with the experiment results. Specifically, we demonstrated that the large vibrational entropy change of Ni–Mn–Ti material originates from the contributions of both the tetragonal distortion ratio and volume change, which provides important theoretical guidance and has great practical significance for designing the solid-state material with large vibrational entropy change in the application of solid-state refrigeration.

Synthesis, magnetic and dye adsorption properties of three metal-organic frameworks based on purine carboxylic acid

Three metal-organic frameworks (MOFs), namely [La(L)Cl(H2O)2]n (1), {[Nd(L)Cl(H2O)3]•2H2O}n (2) and {[Pr2(L)2Cl2(H2O)6]•H2O}n (3), were successfully structured based on ligand 5-((6H-purin-6-yl)amino)isophthalic acid (H2L). X-ray single-crystal diffraction analysis showed that MOFs 1–3 possessed the similar two-dimensional (2D) planar structure. Adsorption experiments showed that MOFs 1–3 exhibited good adsorption effect on Congo red (CR), and their maximum adsorption capacities were 1428, 433 and 319 mg·g−1, respectively. The adsorption kinetics and isotherms showed that the adsorption process conformed to the quasi-second-order kinetic model and the Langmuir model, respectively. The adsorption process belonged to chemical adsorption and monolayer adsorption. The adsorption mechanism mainly involves hydrogen bonding, π-π stacking interaction and electrostatic interaction. In addition, the magnetic test results showed that MOFs 2 and 3 have typically antiferromagnetic behavior.

Study the influence of Ag+ nanoparticles on the surface of the Sr1-xAgxFeO3-δ perovskite on optical, magnetic and antibacterial properties

Recently, we produced low cost SrFeO3-δ perovskite with antibacterial properties. In this study to improve the antibacterial properties of SrFeO3-δ perovskite, we doped it with silver. Ag+ nanoparticles on the surface of the Sr1-xAgxFeO3-δ perovskite samples were prepared by sol-gel method. Structural properties of these samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), high-resolution TEM (HR-TEM), EDS elemental mapping and Fourier transform infrared spectrometer (FT-IR). These techniques confirmed the presence of small amount of cubic Ag spherical nanoparticles on the surface of the cubic Sr1-xAgxFeO3-δ perovskite structure. Further, X-ray photoelectron spectroscopy (XPS) for these samples revealed the presence of Ag1+ ions, oxygen vacancies and mixed valence states of Fe ions on the surface of the samples. The energy band gap of these samples was estimated using Kubelka–Munk equation and its value increased with increasing Ag up to x = 0.10. Additionally, Magnetic hysteresis (M − H) loops revealed that these samples displayed antiferromagnetic behavior with a small amount of ferromagnetic order. Finally, the antibacterial properties of these samples revealed that the antimicrobial activities were improved with increasing Ag (x = 0.10). Our results showed that Ag+ nanoparticles on the surface of the Sr1-xAgxFeO3-δ perovskite samples are a promising antimicrobial agent.Graphical

Structural and magnetic insights of the novel phosphate Ca2NiFe2(PO4)4

One of the primary goals of scientists in the field of materials chemistry is to explore new functional materials, the discovery of new crystal structures and the understanding of their structure-properties relationship. This paper outlines the synthesis of a novel orthophosphate, Ca2NiFe2(PO4)4, in the single crystal and powder forms. The crystallographic analysis reveals that this newly synthesized phosphate exhibits an orthorhombic crystal lattice with the Pbca space group. The crystal structure is composed of PO4 tetrahedra connected to Fe1O6, Fe2O5 and NiO5 polyhedra through shared vertices. This interconnection forms a three-dimensional framework that encloses cavities housing Ca2+ cations. A sol-gel technique was employed to obtain the pure powder. The Rietveld refinement indicates an excellent correlation between the calculated and observed X-ray diffraction patterns. This material was further characterized structurally using infrared and Raman spectroscopy, and morphologically by scanning electron microscopy. The magnetic measurements revealed two magnetic transitions at T1∼8.9 K and T2∼16.5 K suggesting the presence of magnetic frustration with overall dominant antiferromagnetic behavior.

To study structural morphological and ferromagnetic behaviour of Sn1−xMnxO2 thin films

SnO2 is diamagnetic in nature and represent paramagnetic, ferromagnetic and anti-ferromagnetic behaviours after inducing Mn in the host matrix. Mn doped SnO2 thin films prepared by PLD technique. XRD and AFM measurements confirm the reducing crystallite and grain size of the samples with increasing doping of Mn. In this research authors focused on magnetization effect of SMO thin films with the help of SQUID-VSM magnetometer. Magnetic analysis reflects strong ferromagnetic behaviour for (10 % Mn) doping and further increase upto (15 %) shift to ferromagnetic to anti-ferromagnetic behaviour. The above observation will be useful for the core elements for the spintronic devices.

Enhanced multiferroic properties of NZCFO-BNFSO composites: Synthesis, characterization, and performance analysis

The structural and multiferroic properties of xNi0.24Zn0.58Cu0.18Fe2O4(NZCFO)-(1-x)Bi0.9Nd0.1Fe0.95 Sc0.05O3(BNFSO) are explored in this paper. Bi2O3 additives significantly lower the sintering temperature of the composites. The XRD analysis validates the coexistence of hexagonal perovskite BNFSO and spinel NZCFO phases. The FESEM images illustrate an almost homogeneous amalgamation of the BNFSO and NZCFO grains. The real part of initial permeability and the relative quality factor increases with NZCFO contents in the composites. The maximum permeability is observed for the composite with 80 % ferrite content. The ferroelectric BNFSO exhibits antiferromagnetic behavior and with the increase in NZCFO the saturation magnetization increases significantly. The dielectric constant confirms typical dielectric dispersion at low frequencies because of Maxwell–Wagner space charge polarization. The P-E hysteresis measurement reveals that the composite with 40 % ferrite content exhibits the highest loop area and hence a large energy storage capacity. Incorporating BNFSO and NZCFO into the composite boosts the multiferroic properties, which might be a suitable alternative to single-phase multiferroics.

Synthesis and Characterization of a New Archimedean Rhombicuboctahedral Polyoxometalate Rb2.5[(Co(H2O)6)0.5(PW12O40)].16H2O: Probing Magnetic Characteristics and Electrochemical Water Splitting Catalysis

This study describes the synthesis, structure characterization, and magnetic/electrochemical properties of a new Rubidium salt of Cobalt-based Polyoxometalate (POM). A complex Rb2.5[(Co(H2O)6)0.5(PW12O40)].16H2O (Rb-1) was successfully synthesized in a single-pot reaction. The synthesis was done using pre-synthesized [Co2(μ-OH2)(O2CCMe3)4(HO2CCMe3)4] and tri-lacunary Keggin anion Na9[A-α-PW9O34].7H2O. The structure of Rb-1 was verified through Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray (EDX), and single-crystal X-ray crystallography. The crystal structure revealed a cubic crystal system (a, b, c = 22.5801(8) Å and α, β, γ = 90°) with a central Co (II) surrounded by six water molecules. The magnetic properties of Rb-1 were investigated via a superconducting quantum interference device (SQUID), which revealed antiferromagnetic behavior in Rb-1.Moreover, Rb-1 deposited on a Ni-foam electrode with a geometrical area of 1 × 1 cm2 functioned as an anode for efficient oxygen evolution reaction (OER) in water splitting. The Rb-1/Ni-Foam electrode showed excellent overpotential values of 207 mV at 10 mA.cm−2 and 390 mV at 100 mA.cm−2 current densities. The electrode had fast kinetics, as indicated by a low Tafel Slope of 51.76 mVdec−1 and a small charge transfer resistance (RCT) of 5.904 ohms. It exhibited remarkable stability over an 8-hour test period, emphasizing its practical value.

Crossover from relativistic to non-relativistic net magnetization for MnTe altermagnet candidate

Abstract We experimentally study magnetization reversal curves for MnTe single crystals, which is the altermagnetic candidate. Above 85 K temperature, we confirm the antiferromagnetic behavior of magnetization M, which is known for α–MnTe. Below 85 K, we observe anomalous low-field magnetization behavior, which is accompanied by the sophisticated M(α) angle dependence with beating pattern as the interplay between M(α) maxima and minima: in low fields, M(α) shows ferromagnetic-like 180° periodicity, while at high magnetic fields, the periodicity is changed to the 90° one. This angle dependence is the most striking result of our experiment, while it can not be expected for standard magnetic systems. In contrast, in altermagnets, symmetry allows ferromagnetic behavior only due to the spin-orbit coupling. Thus, we claim that our experiment shows the effect of weak spin-orbit coupling in MnTe, with crossover from relativistic to non-relativistic net magnetization, and, therefore, we experimentally confirm altermagnetism in MnTe.

Appraising the structural and magnetic properties in template assisted neodymium based metal organic frameworks

This study demonstrates synthesis of two novel lanthanide-based metal-organic frameworks, namely [{NdIII(5 N3-H2isa)2(H2O)2}(H2O)2}]∞ (1) and [{NdIII(5 N3-H2isa)2(H2O)2}(H2O)(1,2-PE)}]∞ (2), synthesized via solvothermal methods using 5-azidoisophthalic acid (5 N3-H2isa) and NdCl3. Both compounds were extensively characterized using single crystal X-ray diffraction, as well as other physicochemical techniques such as IR, TGA, PXRD, and elemental analysis. Structural differences were observed in both compounds depending on the nature of the template molecule used. Compound 1 exhibits an infinite 2D architecture with lattice-occluded water molecules within the 2D layers. In contrast, compound 2, where 1-(-2-pyridyl)-2-(4-pyridyl)ethylene (1,2-PE) was used as the template, shows replacement of interstitial water molecules by the template molecule, resulting in significant changes in overall pore topology which is further corroborated by BET analysis. These structural variations were further supported by magnetic behaviour analyses, indicating an antiferromagnetic behaviour for both compounds.

Heterometallic [FexM3–x(μ3-O)] cluster-based metal–organic frameworks for magnetic properties

In the paper, we construct a class of heterometallic [FexM3–x(μ3-O)] cluster-based MOFs (PCN-250 (Fe2M), M = Fe3, Fe2Co, Fe2Ni and Fe2Co0.5Ni0.5) through modularization by solvothermal method. The structures of PCN-250 (Fe2M) contain heterometallic [FexM3–x(μ3-O)] cluster by carboxylate bridges and further connected with 3,3 ’, 5,5′ − azobenzene tetracarboxylic acid to form 3D networks. Moreover, magnetic investigations indicate that PCN-250 (Fe3) and PCN-250 (Fe2Co) possess antiferromagnetic behavior, while PCN-250 (Fe2Ni) and PCN-250 (Fe2Co0.5Ni0.5) display canted antiferromagnetic behavior with weak ferromagnetism.