Magnetic Coupling Properties Research Articles

MXene@Fe3O4/PDA nanosheets with photothermal-magnetically coupled antibacterial properties

Pathogenic infections pose a major threat to global public health, and what's worse is that the bacteria in infected places often exist in the form of biofilms, making it impossible for antibiotics and other contact bactericidal substances to penetrate their interior. Therefore, looking for an effective method with synergistic antibacterial and biofilm removal properties is a key challenge. A kind of magnetic MXene@Fe3O4/PDA nanosheets with antibacterial properties of photothermal magnetic coupling are reported in this paper. Fe3O4 was grown in situ on MXene nanosheets and then coated with a layer of polydopamine (PDA). MXene@Fe3O4/PDA nanosheet (120 μg/mL) showed an over 95% inhibition rate against E. coli and S. aureus under 808 nm laser irradiation. In addition, peroxidase-like activity can produce reactive oxygen species. The photothermal antibacterial properties were further enhanced under the action of rotating magnetic field. The antibacterial activity was increased to close to 99.99%, and the removal effect of biofilm was also very good. The photothermal and magnetic coupled antibacterial effects can reduce the amount of MXene@Fe3O4/PDA, thus it is expected to reduce the damage caused by overheating normal tissues and is safer than pure photothermal therapy.

Mutual control of electric and magnetic orders near room temperature in Al doped Y-type hexaferrite single crystals

Realizing robust magnetoelectric (ME) coupling effect near room temperature is still a long-standing challenge for the application of multiferroic materials in next-generation low-power spintronic and memory devices. Here we report a systematic study on the magnetic, dielectric, and ME coupling properties of Y-type hexaferrite Ba0.5Sr1.5Co2Fe12–xAlxO22 (x = 0.0, 0.5, 1.0) single crystals. The Al doping can induce the shifting of the alternating longitudinal conical (ALC)-proper screw (PS) magnetic phase transition temperature from 200 K for x = 0–365 K for x = 1.0. The most interesting feature is that the Ba0.5Sr1.5Co2Fe11AlO22 single crystal displays a direct and converse ME coupling coefficient with αH ∼3,100 ps/m and αE ∼3,900 ps/m at 250 K, respectively, due to the Al-doped enhanced stability of ALC phase. Moreover, the exchange bias also verifies the strong coupling of electric and magnetic orders. These results provide a valuable insight on the modulation of ALC structure and the mechanism of ME effect in Y-type hexaferrites.

Effect of rapid/slow annealing routes on the magnetic and photoelectric properties of BiFeO3/CoFe2O4 multilayer thin films

With the development of electronic information technology, the miniaturization of lightweight devices and their integration have increased the requirements for materials, and two-dimensional composite multiferroic materials have become a major research hotspot in recent years. However, it is difficult for traditional solid multiferroic material to directly switch the magnetic/polarization direction under the action of an applied electric/magnetic field, limiting the improvement of the magnetoelectric coupling coefficient. In this study, a series of BiFeO3 (BFO)/CoFe2O4 (CFO) composite film multiferroic materials were prepared by changing the annealing routes and annealing atmosphere, the microstructure, ferroelectric properties, dielectric properties, photovoltaic properties, magnetic properties, and magnetoelectric coupling properties of composite films were routeatically studied. The results showed that under the slow annealing route, the composite film has obvious ellipsoidal grains with distinct grain boundaries and better crystallinity. Moreover, the performance of the film after annealing in different atmospheres of the slow annealing route was improved compared with that of the rapid annealing route after annealing in different atmospheres. Simultaneously, by changing the annealing atmosphere of the composite film, the film exhibited better magnetic optical properties and coupling properties after annealing in oxygen. In addition, this study showed that the dielectric constant and residual polarization value of the film increase under the action of magnetic field and illumination, and the maximum photomagnetic dielectric response (3.19%) and photomagnetic response (1.58%) are observed in the annealed film under the oxygen atmosphere of the slow annealing regime, indicating that the magnetoelectric coupling effect of the film is improved under the action of applied light.

Origin of Weak Magnetic Coupling in a Dimanganese(II) Complex Bridged by the Tetrathiafulvalene-Tetrathiolate Radical.

Magnetic exchange coupling (J) between different spin centers plays a crucial role in molecule-based magnetic materials. Direct exchange coupling between an organic radical and a metal is frequently stronger than superexchange through diamagnetic ligands, and the strategy of using organic radicals to engender desirable magnetic properties has been an area of active investigation. Despite significant advances and exciting bulk properties, the magnitude of J for radical linkers bridging paramagnetic centers is still difficult to rationally predict. It is thus important to elucidate the features of organic radicals that govern this parameter. Here, we measure J for the tetrathiafulvalene-tetrathiolate radical (TTFtt3-•) in a dinuclear Mn(II) complex. Magnetometry studies show that the antiferromagnetic coupling in this complex is much weaker than that in related Mn(II)-radical compounds, in contrast to what might be expected for the S-based chelating donor atoms of TTFtt. Experimental and computational analyses suggest that this small J coupling may be attributed to poor overlap between Mn- and TTFtt-based magnetic orbitals coupled with insignificant spin density on the coordinating S-atoms. These factors override any expected increase in J from the comparatively strong S-donors. This work elucidates the magnetic coupling properties of the TTFtt3-• radical for the first time and also demonstrates how multiple competing factors must be considered in rationally designing organic radical ligands for molecular-based magnetic compounds.

Hexaguanidino-Triptycenes and Triphenylenes: Electronic Coupling in Molecules Containing Three Redox-Active o-Diguanidinobenzene Units Connected either Directly or Interacting Through Homoconjugation.

Novel redox-active hexaguanidine molecules with multiple redox states were synthesized by connecting three o-diguanidinobenzene units. In 2,3,6,7,14,15-hexaguanidino-triptycenes, the three redox-active o-diguanidinobenzene units are connected through C-C bonds to the sp3 -hybridized bridgehead C atoms, and in 2,3,6,7,10,11-hexaguanidino-triphenylenes they are directly connected. The connectivity difference leads to different electronic coupling between the three redox-active o-diguanidinobenzene units, with homoconjugation being present in the triptycene, but not in the triphenylene compounds. Motivated by the appearance of an intense low-energy electronic transition, we especially analysed the effect of homoconjugation on the electronic structure and charge delocalization in the dicationic redox state of the triptycene derivatives. Then, several trinuclear high-spin cobalt (and copper) complexes were synthesized with the triphenylene and triptycene ligands, and the magnetic coupling and redox properties analysed. By choice of the coligands (hexafluoroacetylacetonate, trifluoroacetylacetonate and acetylacetonate), oxidation could be switched between metal- and ligand-centered redox events, leading to drastic changes in the magnetic or optical properties, especially as a consequence of homoconjugation in the triptycene derivatives.

Magnetic coupling properties of multiple metal wear particles for high-precision electromagnetic debris detection applications

The electromagnetic wear particle detector is one of effective method to monitor wear debris in lubricating oil for assessing the wear condition of mechanical equipment. However, the motion of wear particles, especially the aggregation behavior in both fluid field and magnetic field, may make the particle detector generate false wear signals. Therefore, to estimate the impact on the detection accuracy of wear debris by the particle aggregation effect, the magnetic coupling model of multiple wear particles is established for studying the magnetic coupling effect between adjacent metal particles. The research results show that the effect changes the total magnetic energy variation induced by the particles and then affects the amplitude of particle signal. Meanwhile, the variation degree is closely associated with the frequency of magnetic field of particle detectors. Overall, the aggregation of wear particles with the same magnetic properties (both ferromagnetic or non-ferromagnetic) leads to false alarms of particle detectors; and the aggregation of wear particles with different magnetic properties causes missing alarms of particle detectors. Meanwhile, increasing the field frequency may increases the probability of missing alarm failure of particle detectors.

C and N effect on magnetic coupling and vibrational properties of bcc and fcc-FeMnCr alloys: DFT study

In this work we report, magnetic and thermal properties of the bcc-Fe0.52MnxCr0.28-xCu0.06Mo0.10C0.012N0.014 (xMn = 5.77, 11.51 and 17.22 wt%) and the fcc-Fe0.63MnxCr0.26-xCu0.03Mo0.05C0.006N0.007 (xMn = 8.98, 11.95 and 14.92 wt%) alloys, applying the pseudo-potential Density Functional Theory (PP-DFT). The obtained results show that magnetic properties of these alloys are governed by Mn concentrations and C, N additions. The magnetic moments at each atom depend strongly on Mn concentrations as well as on the presence of C, N atoms. The C, N or both CN additions into octahedral sites do not affect the magnetic coupling between atoms. The quasi-harmonic Debye model is successfully applied to predict thermal properties of these alloys. The bulk modulus, volume expansion and Gibbs free energy are significantly affected by temperature, Mn concentrations and C, N additions in both bcc and fcc alloys. Whereas, vibrational entropy is more affected by bcc–fcc phase transition than C, N addition and Mn concentration.

Manipulating topological Hall-like signatures by interface engineering in epitaxial ruthenate/manganite heterostructures.

Topologically protected non-trivial spin textures (e.g. skyrmions) give rise to a novel phenomenon called the topological Hall effect (THE) and have promising implications in future energy-efficient nanoelectronic and spintronic devices. Here, we have studied the Hall effect in SrRuO3/La0.42Ca0.58MnO3 (SRO/LCMO) bilayers. Our investigation suggests that pure SRO has hard and soft magnetic characteristics but the anomalous Hall effect (AHE) in SRO is governed by the high coercivity phase. We have shown that the proximity effect of a soft magnetic LCMO on SRO plays a critical role in interfacial magnetic coupling and transport properties in SRO. Upon reducing the SRO thickness in the bilayer, the proximity effect becomes the dominant feature, enhancing the magnitude and temperature range of THE-like signatures. The THE-like features in bilayers can be explained by a diffusive Berry phase transition model in the presence of an emergent magnetic state due to interface coupling. This work provides an alternative understanding of THE-like signatures and their manipulation in SRO-based heterostructures, bilayers and superlattices.

Aliovalent Calcium Substitution: An Effective Way to Enhance the Magnetoelectric Coupling Properties of Multiferroic BiFeO3

Kinetics of magnetoelectric coupling in bismuth ferrite (BiFeO3) with the substitution of aliovalent calcium ion is investigated. The resulting structural, dielectric, magnetic, and magnetoelectric (ME) coupling properties are explained in terms of chemical pressure originating from the substituent ion. Substitution of calcium finds to reduce the oxygen vacancies. Two important substitution concentrations find to be critical in ferroelectric (FE) and ME coupling properties. At 10 at% calcium, highest remanent polarization is obtained and maximum ME coupling coefficient is observed at 20 at%, which suggests calcium concentration between 10% and 20% can be optimized to obtain good electrical and ME coupling properties of BiFeO3. Maximum ME coupling coefficient at calcium concentration 20 at% is close to numerical calculations reported in the literature. Magnetic properties are also favorably modified by the substitution; a coupled antiferromagnetic and weak ferromagnetic ordering is obtained. Also, a variation in blocking temperature and spin relaxation is observed with respect to the substituent ion concentration.

Theoretical Simulation on Regulating the Magnetic Coupling Properties of Diradical Artificial Bases.

In this work, we computationally designed a series of diradical molecules with obvious magnetic coupling properties based on newly synthesized artificial bases, 6-amino-3-(1'-β-d-2'-deoxyribofuranosyl)-5-nitro-1H-pyridin-2-one (Z), 2-amino-8-(1'-β-d-2'-deoxyribofuranosyl)-imidazo-[1,2a]-1,3,5-triazin-[8H]-4-one (P), 6-amino-9[(1'-β-d-2'-deoxyribofuranosyl)-4-hydroxy-5-(hydroxymethyl)-oxolan-2-yl]-1H-purin-2-one (B), and found two methods (base pairing and nitro group rotation) of regulating the magnetic magnitude, making them become magnetic switches with promising prospects. On one hand, the modified diradical artificial base P3 possesses an excellent magnetic exchange coupling constant due to its spin density concentration on a unique spin polarization path. Because of the serious mismatch between the singly occupied molecular orbital (SOMO) and the lowest unoccupied molecular orbital (LUMO) of Z-P3 base pairing, the magnetic coupling property of the Z-P3 base pair disappears, which indicates that the base pairing can be used as an effective means to regulate the molecular magnetic coupling properties. On the other hand, the investigation shows that the rotation of the nitro group on Z has an influence on the energy gaps between the closed-shell (CS) singlet and triplet (T) states of the base pairs formed by Z-analogues and thereby the expression of magnetic coupling properties. This work can help to develop the modification strategy of the diradical base and provide theoretical guidance for the design and synthesis of magnetic coupling materials with controllable magnetic coupling properties.

Direct evidence of mutual control of ferroelectric polarization and magnetization in Y-type hexaferrite BaSrCo2Fe12-Al O22 ceramics

Hexaferrites that exhibit the intrinsic and strong magnetoelectric (ME) coupling effect have been considered the most promising candidate for single-phase multiferroics. Currently, the strong ME coupling effect in this system was widely reported in single crystal form, while it is rare in polycrystalline one. In this work, Y-type hexaferrite BaSrCo2Fe12-xAlxO22 (x = 0.0, 0.3, 0.6 and 0.9) ceramics were manufactured with conventional solid-state reaction. Their magnetic, dielectric, and ME coupling properties were systematically surveyed. It was revealed that Al doping could result in a high magnetic transition temperature of ~ 345 K for x = 0.9. Also, the ferroelectric polarization and abnormal magnetodielectric properties were significantly enhanced which could be maintained down to 200 K. Most interestingly, the sample x = 0.9 displayed strong direct and converse ME coefficients of ~ 400 ps/m and ~ 900 ps/m at 150 K, respectively. Therefore, these results reveal that Al doping can broaden our understanding of the Y-type hexaferrite in room-temperature multiferroics.

BaTiO3/(Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4)x composites: Analysis of the effect of Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4 doping at different concentrations on the structural, morphological, optical, magnetic, and magnetoelectric coupling properties of BaTiO3

In the present study, composite samples of BaTiO3/(Co0.8Ni0.1Mn0.1Fe1.9Ce0.1O4)x (noted as BTO/(CNMFCO)x) were prepared and their structural, morphological, optical, magnetic, and magnetoelectric coupling properties were investigated. Firstly, the BaTiO3 and spinel ferrite CNMFCO phases were prepared separately through the sol-gel auto-combustion route, then, the composite samples BTO/(CNMFCO)x were made via the solid-state reaction method. The structural, morphological, optical, magnetic, and magnetoelectric coupling properties were examined using X-rays diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electron microscope (SEM) coupled with EDX spectrometer, UV–visible diffuse reflectance spectrophotometer (UV–vis DRS), vibrating sample magnetometer (VSM) techniques, and lock-in amplifier, respectively. The successful preparation of biphasic samples was confirmed by XRD and SEM studies. From SEM images, a compact structure with good density was observed. The mean size of BTO grains decreases with increasing the concentration of the magnetic phase. The optical properties have been explored in the UV–visible light range. The extracted band gap energy (Eg) values showed a reduction with the rising of the magnetic phase content. The analysis of magnetization measurements revealed the magnetic character of different composites. It is found that the saturation (Ms) and remanent (Mr) magnetizations are increasing with the rise in the concentration of the magnetic CNMFCO phase (x %). High magnetoelectric voltage coefficients (αME) were attained for different composites with the highest αME value of about 22.8 mV/cm.Oe reached in composite with x content of 20%. The high ME coupling in these composites makes these composites promising candidates to be used in multifunctional devices.

Endohedral σ-Diradical Nitrogen-Vacancy Diamond Nanoclusters with a Confined Magnetic Space and Strong Electronic Spin Couplings.

The electronic properties and their modulations for the nitrogen-vacancy (NV) centers in various nanoscale diamonds are of profound current interest because of their potential applications. However, although the NV centers as chromophores in diamond are the most widely studied, surprisingly, little is known about their magnetic spin coupling properties up to now. Here, we for the first time show, using the spin-polarized DFT calculations, that the NV centers can act as unique endohedral σ-diradical magnets in diamond nanoclusters and exhibit quite strong ferromagnetic (FM) or antiferromagnetic (AFM) spin coupling characteristics due to their unique endotetrahedral structures with favorable radical-radical contacts. Although the neutral NV center (NV0) in its doublet ground state exhibits quite strong AFM spin coupling among three radical C-sites (i.e., an AFM triradical center), interestingly, excess electron injection can convert it to a FM diradical magnet (i.e., the triplet ground state NV-) with almost unchanged J-coupling magnitude, and the J-coupling of the nanocluster can be noticeably enhanced by F-termination of the surface due to triradical spin delocalization mediated by excess electron. However, interior modification (one C in the endotetrahedron core is substituted by N or B or is hydrogenated) can assign the nanocluster perfect AFM diradical character. The spin coupling strength presents a quasilinear correlation with the distance between the two C radicals in the NV core for the same size of the clusters and a high linear correlation with the energy difference between two singly occupied molecular orbitals. Clearly, the FM and AFM couplings as well as their switching behavior in such NV defect diamond nanoclusters featuring the endohedral σ-diradicals are a novel type of promising magnetic material motifs. These findings open up promising spintronic application prospects of the NV diamonds and provide helpful information for the design of inorganic magnetic materials and logic devices.

Compositional dependence of structural, magnetic and spin-phonon coupling properties in Fe2−xGaxO3 (x = 0.6–1.2) system with orthorhombic symmetry

A combined technique of mechanical alloying and heat treatment has been used to prepare the polycrystalline samples of Fe2−xGaxO3 (x = 0.6–1.2) system in orthorhombic phase. It has been possible to reduce the sintering temperature by ~350 °C for stabilizing the orthorhombic phase in comparison to the temperature reported in literature. The Rietveld refinement of X-ray diffraction patterns indicated the distribution of Ga and Fe atoms in the Ga1, Ga2, Fe1 and Fe2 sites of the lattice structure. A linear variation of the lattice parameters with Ga/Fe content showed application of Vegard’s law. The temperature-dependent magnetization measurements confirmed ferrimagnetic order of Fe spin moments. The ferrimagnetic transition temperature (TC) has decreased from 320 K to 100 K with the increase of Ga content in the range of x = 0.6–1.2. Temperature-dependent Raman spectroscopy data ruled out any structural phase transition at TC, but an anomalous behaviour of the position and width of the peaks of Raman active phonon modes near to TC confirmed a strong spin–phonon coupling in the material. The spin–phonon coupling strength (η) for the A9 mode has been found around 1.64 cm−1 for x = 1 and 3.34 cm−1 for x = 0.8, and η for the A21 mode has been found around 2.12 cm−1 for x = 1 and 3.28 cm−1 for x = 0.8. The spin-phonon coupling strength has been diluted in the samples with higher content of Ga. The experimental results indicated that the variation of Ga/Fe content and its distribution in lattice sites determine the ferrimagnetic properties, magnetic anisotropy and spin-phonon coupling in Fe2−xGaxO3 system. The results are expected to be useful for understanding the spin-phonon coupling in multiferroic-magnetoelectric materials with magnetic and electric transitions near to room temperature.

Electronic, magnetic and photocatalytic properties of Si doping in g-ZnO monolayer with point defects

The electronic structures, magnetic properties, magnetic coupling and photocatalytic properties of Si-doping (4 × 4) graphene-like ZnO (g-ZnO) monolayer without or with defects including V O and V Zn have been calculated using the first-principles method. Si doping ZnO can increase the electronic state near Fermi level and introduce impurity state into the band gap due to P-type doping. The impurity state introduced by Si doping makes the system transition from NM to FM. The analysis of E f indicates that Si doping makes ZnO thin films easy to form V Zn . V O leads to two weakly bound Zn-4s electrons, V Zn leads to two weakly bound O-2p electrons, both of them can form impurity level near Fermi level, thus affecting the magnetic properties of g-ZnO monolayer. The analysis of magnetic coupling characteristics shows that the doping system undergoes a transition from NM to FM. Because the impurity state introduced by Si doping is beneficial to the excitation of electrons, Si doping can also reduce the gap between Fermi level and conduction band. The calculation result of optical properties shows that Si doping has strong absorption to visible light. • Si doping g-ZnO increases the electronic state of Fermi level and introduce impurity state into the band gap. • Si doping ZnO, V O and V Zn are the ferromagnetic origin of g-ZnO monolayer. • Si doping can reduce the gap between Fermi level and conduction band. • Si doping can improve the absorption of g-ZnO in the visible range.

On the magnetic and magnetoelectric coupling properties of lead-free (1 − x) Bi0.9La0.1FeO3/xLa0.7Sr0.3MnO3 (x = 0, 0.1, 0.2) composites at room temperature

On the magnetic and magnetoelectric coupling properties of lead-free (1 − x) Bi0.9La0.1FeO3/xLa0.7Sr0.3MnO3 (x = 0, 0.1, 0.2) composites at room temperature

Polaron Hopping Induced Giant Room‐Temperature Magnetodielectric Effect in Disordered Rutile NiNb2O6

AbstractA majority of the existing magnetodielectric (MD) effects based on spin‐lattice coupling or magnetic transitions are either too weak or far below room temperature, which challenges the potential applications of MD materials. Here, a giant room‐temperature MD coefficient of −62% at 1 Tesla (T) in disordered rutile NiNb2O6 (r‐NiNb2O6) ceramic in terms of the spin‐dependent polaron hopping is demonstrated. The r‐NiNb2O6 exhibits a near‐room‐temperature dielectric relaxation, which is ascribed to the polaron‐hopping‐induced grain polarization. This dielectric relaxation process, strikingly, can be controlled by the external magnetic field (H = 1 T) at 220 K< T< 310 K, achieving a giant MD coefficient of −62% (at 10k Hz) at 298 K. Further systematic investigations on the magnetic, electrical, and magnetoelectric coupling properties attribute the MD effect in r‐NiNb2O6 to a pure response of the spin‐dependent polaron hopping to applied magnetic field. This clearly reveals that the MD effect is subject to a competition among the polaron hopping activation, spin‐lattice coupling, and spin thermal fluctuation.

Antiferromagnetic metallic state and low-temperature magnetoresistance in epitaxial La0.85Sr0.15MnO3 films

We report the magnetic coupling and magneto-transport properties of the epitaxial La0.85Sr0.15MnO3 films, which are fabricated on the (001)-oriented SrTiO3 substrate by RF magnetron sputtering. The anti-ferromagnetism and metallic state were observed in sequence, and both coexist below a critical temperature of 40 K. Meanwhile, the hysteresis loop exhibits the spin-flop transition. The antiferromagnetic phase originates from the A-type spin structure, in which the antiferromagnetic superexchange interaction between the adjacent MnO2 planes is along the c-axis direction. The metallic behavior stems from the double exchange interaction in the MnO2 plane in-plane. Furthermore, the spin scattering at phase boundaries between the ferromagnetic and antiferromagnetic phases causes a comparatively large magnetoresistance value of about −30% around 100 K. This effect, together with the colossal magnetoresistance, causes the large magnetoresistance values in a wide temperature range. This work helps to understand the magnetic coupling of the antiferromagnetic metallic state and magneto-transport properties in lightly doped manganite films.

Enhancement and recovery of magnetic exchange coupling properties in SrFe11AlO19@NiFe2O4 core-shell structure by multiple TiO2 and SiO2 nanolayer shells

The exchange coupling of magnetic hard/soft SrFe11AlO19@NiFe2O4 (SFAO@NFO) core-shell structure was investigated by taking into consideration the effects of TiO2 (TO) and SiO2 (SO) nanoparticles as multiple shells. The SFAO@NFO core-shell structure was synthesized via an auto-combustion sol-gel method. The NFO nanolayer caused the resulting saturation magnetization, magnetic remanence and coercivity of SFAO to be reduced from 43.18 emu/g, 24 emu/g and 5500 Oe to 17.13 emu/g, 7.74 emu/g and 2300 Oe, respectively. This was attributed to the NFO performance as a magnetic dead layer (MDL), and to the SFAO@NFO exchange coupling effect. The TO and SO nanolayers were also synthesized via a templating approach and a modified Stöber method, respectively, in order to act as additional shells and capping layers, recovering magnetic properties of the initial core-shell structure. It was found that the TO nanolayer shell can serve as a room-temperature ferromagnetic material due to its surface defects and oxygen vacancies. The TO and SO nanolayer shells increased the saturation magnetization, and magnetic remanence of SFAO@NFO from 17.13 to 30.51 and 34.10 emu/g, and 7.74 to 11.57 and 14.06 emu/g, respectively, while also decreasing the coercivity from 2300 Oe to 600 and 850 Oe, respectively. As a result, the additional shells enhanced magnetic exchange coupling properties of SFAO@NFO core-shell structure by removing the effect of the MDL.

Regulating synchronous patterns in neurons and networks via field coupling

Both electrical and chemical synapses play important role in receiving and propagating signals between biological neurons. The activation of electrical synapse coupling is generated via gap junction connection while chemical synapse coupling depends on the release of neurotransmitter for triggering stable propagation of ions. In a practical way, voltage coupling via resistor connection between artificial neural circuits is often used to describe the gap junction coupling via electrical synapse between neurons. Magnetic field coupling via induction coil between neural circuits can be effective to estimate the chemical synapse coupling when ions are propagated and released in the cell. In this paper, the physical properties of magnetic field coupling between neural circuits are discussed. For simplicity, two Hindmarsh–Rose neurons are connected to trigger magnetic field coupling and the coupling channel is tamed to detect possible occurrence of synchronization. Two neurons are stimulated with different stimuli, and it is confirmed that the synchronous firing mode is decided by the neuron with higher forcing amplitude. Furthermore, the collective behaviors of HR neuron in the small-world network and scale free network are investigated by changing the coupling intensity and diversity in external stimulus, respectively. Statistical synchronization factor is calculated to estimate the dependence of synchronization on coupling gain and the number of bursting neurons in the network. In case of small-world connection, synchronization approach becomes difficult. However, complete synchronization can be stabilized on the scale free network under magnetic field coupling.