Magnetic Properties Of Mg Research Articles

Unraveling the structural and magnetic characteristics of Mg doped CoCr2O4

In this paper, we explore the structural and magnetic properties of Mg doped CoCr2O4nanopowder (typical size of 10 nm) synthesized via the sol–gel auto-combustion method. X-ray diffraction, XPS, and FTIR spectraconfirm spinel structure (space group Fd-3 m) with Mg2+ doped at Cr3+. Interestingly, temperature-dependent magnetizations show various magnetic transitions between 5–300 K. While they show ferrimagnetic ordering below Curie temperature of 100 K (CoCr2O4) to 80 K (CoCr1.8Mg0.2O4) samples, the irreversibility betweenFC and ZFC curves at blocking temperature attribute to spin blocking nature of nanoparticles. Finally, at very low temperatures (13–26 K), magnetizations again rise indicating spin-spiral transition of CoCr1.8Mg0.2O4.Furthermore, the effect of these transitions onM−H loopcan be evidentin terms of coercivity, saturation magnetization, andnon-saturation behaviorat high magnetic fields.

Curie temperature and magnetic permeability regulation of Cr–Mg co-doped NiCuZn ferrite for tumor hyperthermia

The controllable Curie temperature and high magnetic permeability of NiCuZn ferrites make them promising candidates for magnetic thermal medium. However, the temperature control of existing NiCuZn ferrite materials is not accurate enough to achieve the low Curie temperature required for tumor hyperthermia. In order to further achieve the desired Curie temperature and facilitate the advancement of temperature control materials for tumor hyperthermia, Cr–Mg co-doped NiCuZn ferrite was studied. The study investigated the influence of varying concentrations of Cr3+ on the crystal structure and magnetic properties of Mg–NiCuZn ferrites. The results of structural characterization demonstrate that Cr–Mg co-doped NiCuZn ferrites exhibit high density and uniform distribution of elements. The introduction of Cr3+ leads to a reduction in lattice parameters and a preference for octahedral B-sites. The hysteresis loop results show that the saturation magnetization first increases and then decreases with the increase of Cr3+ concentration. Ni0.09Mg0.20Cu0.14Zn0.60Fe1.89Cr0.050O3.94 ferrite at 0.30 wt% of Bi2O3 exhibits optimal magnetic characteristics, including a saturation magnetization of ∼36.7 emu/g, low coercivity of ∼0.07 kA/m, high permeability of ∼982.43 @1 MHz, and an appropriate Curie temperature of 45.59 °C. Such permeability and Curie temperature can be used in the body cavity perfusion hyperthermia and deep thermal therapy.

A Comparative Study on the Effect of Different Sintering Temperatures on Structural and Magnetic Properties of Mg–Zn Ferrite Nanoparticles

The current study involved the synthesis of magnesium zinc ferrite (Mg0.8Zn0.2Fe1.4Al0.6O4) using the sol–gel method. Various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), vibrating sample magnetometer (VSM), and radiofrequency (RF) induction were utilized to analyze the properties of the synthesized ferrite nanoparticles. The objective was to examine how different sintering temperatures affected the structural and magnetic characteristics of Mg0.8Zn0.2Fe1.4Al0.6O4. The XRD analysis confirmed the presence of a well-defined single phase crystalline structure with a spinel arrangement. Increasing the annealing temperature resulted in larger nanoparticles, ranging from 28.38 nm to 30.14 nm. SEM provided information about the morphology, agglomeration, and grain size of the ferrite, revealing a grain size ranging from 326 nm to 485 nm. The FTIR spectroscopy indicated a single-phase spinel structure for the prepared sample. The magnetic properties of the sample were evaluated using VSM, showing a maximum magnetization of 45.6 emu/gm and the least coercivity of 90 Oe at an annealing temperature of 900 °C. RF induction at a frequency of 108 kHz exhibited superior results for the sample annealed at 900 °C compared to those annealed at 700 °C and 800 °C. At this frequency, the specific absorption rate (SAR) value was high, making it suitable for magnetic hyperthermia applications. The prepared magnesium zinc ferrite demonstrated suitability for both low and high frequency devices, and it could be employed in various technological applications, including microwave devices, inductor cores, transformers, and other electronic devices.

Tuning structural, electrical, dielectric and magnetic properties of Mg–Cu–Co ferrites via dysprosium (Dy3+) doping

In current research work, Dy3+ substituted Mg0.5Cu0.25Co0.25Fe2‒xDyxO4 (0.0 ≤ x ≤ 0.04 with the step interval of 0.01) soft ferrites were synthesized by the sol–gel auto combustion method. The prepared samples were characterized by the techniques using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, current–voltage (I–V) measurement, LCR meter, vibrating sample magnetometer (VSM) and Raman. XRD data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x = 0.03. The non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX analysis. The DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in temperature. Moreover, the high resistivity is observed with the order of 1010 Ω·cm, and the activation energy is 0.944 eV for samples x = 0.03. The dielectric parameters including dielectric constant, dielectric losses, and impedance gradually decrease with the increase in frequency from 8 Hz to 8 MHz. The minimum dielectric loss at high frequency is found for sample x = 0.03. The coercivity (Hc) and saturation magnetization (Ms) are found in the ranges of 520.82–544.02 Oe and 20.5841–21.1473 emu/g, respectively. These observations confirm that dysprosium (x = 0.03) doped MCC-soft ferrites may be applicable in transformer cores, microwave absorbance, and telecommunication devices.

Study of the magnetic properties of Mg, Gd, and Co doped maghemite (γ-Fe2O3) nanoparticles prepared by sol–gel

The γ-Fe2O3 magnetic nanoparticles, prepared by sol gel route, were doped with Magnesium (Mg), Gadolinium (Gd), and Cobalt (Co) oxides to enhance their magnetic properties. The X-ray diffraction, of the prepared samples, show that all samples crystallized under cubic structure with P4332 space group. The morphological properties of our nanopowders were studied with TEM investigations. The average nanoparticle sizes were distributed between 15 and 23 nm for both the pure and the doped samples. The magnetization as a function of temperature and magnetic field were measured to study the effect of the doping elements on the magnetic properties. The results show that the highest magnetization (MH) of our nanoparticles increases especially with increasing Mg, Gd and Co concentration It is also observed that cobalt doping increases the magnetic coercivity by increasing the value of the coercivity field (Hc) and remanence magnetisation (Mr), which can be used in magnetic recording devices.

Investigation on the microstructure and magnetic properties of Mg(Ga2−xFex)O4 spinel ferrites

Investigation on the microstructure and magnetic properties of Mg(Ga2−xFex)O4 spinel ferrites

Comparison of Structural, dielectric and magnetic investigation of Cr3+ substituted Mg-Cu, Mg-Zn, and Mg-Ni ferrites system

• Studied the effect of Cr 3+ substitution on the structural, dielectric, and magnetic properties of Mg 0.5 M 0.5 Fe 1.5 Cr 0.5 O 4 (M = Cu, Zn, and Ni) ferrite system prepared by sol–gel method. • The XRD patterns showed a single spinel phase. • The magnetic saturation (M s ), magnetic moment (M r ), and Coercivity (H c ) is found to be the highest for the Cr substituted Mg-Ni ferrite system. • All the synthesized samples showed ferrimagnetic behavior. • Thus, the magnetic and structural properties of (Mg 0.5 M 0.5 Fe 1.5 Cr 0.5 O 4 (M = Cu, Zn, and Ni) NPs can be favorable for their potential use in high-density recording media applications. Effect of Cr 3+ substitution on the structural, dielectric, and magnetic properties of Mg 0.5 M 0.5 Fe 1.5 Cr 0.5 O 4 (M = Cu, Zn, and Ni) ferrite system prepared by sol–gel method. All ferrites prepared samples’ powder; X-ray diffraction patterns confirmed the formation of single-phase cubic spinel structures with Fd -3 m space group. It possesses a monophasic cubic-spinel lattice structure with an average crystallite size ranging from 25 to 44 nm. The lattice constant determined by XRD analysis falls between 8.497 Å and 8.392 Å. Furthermore, the crystallite size determined by XRD data is well matched with the particle size determined by scanning electron microscopy images. Using an LCR Meter, the dielectric parameters of the samples, such as dielectric constant ( ε ’) and dielectric loss tangent (tan δ ), were studied as a function of frequency in the range of 100 Hz to 5 MHz at room temperature. The dielectric constant and loss tangent among the samples show a normal dielectric behavior with a frequency which reveals that the dispersion is a result of the Maxwell-Wagner type interfacial polarization and hopping of electrons between the Fe 2+ and Fe 3+ ions. The hysteresis curve exhibits the particles are soft ferrimagnetic with maximum saturation magnetization, Ms = 38.55 emu/g due to Cr substituted Mg-Ni ferrite. The squareness ratios were discovered to be less than 0.5, indicating that our particles have a single-domain ferrimagnetic isotropic nature. Thus, the magnetic and structural properties of (Mg 0.5 M 0.5 Fe 1.5 Cr 0.5 O 4 (M = Cu, Zn, and Ni) NPs can be favorable for their potential use in high-density recording media applications.

Photocatalytic and magnetic properties of Mg substituted cobalt ferrite

Single-phase magnesium doped cobalt ferrites have been synthesized by the sol–gel combustion technique. The structural investigations of Co1−xMgxFe2O4 (x = 0.25, 0.5, and 0.75) confirm the single-phase cubic spinel structure with an average crystallite size of 38.96, 34.62, and 32.94 nm, respectively. Cubic morphology is observed by the field emission scanning electron microscopy (FE-SEM). The direct bandgap energy values are calculated by Tauc’s plot and it reveals the increase in bandgap values from 1.35 to 1.46 eV with Mg substitution. The thermal stability showed residue of 97.14 %, 95 %, and 96.95 % for x = 0.25, 0.5, and 0.75, respectively. The magnetic behavior of the samples exhibited a decrease in saturation magnetization (Ms) from 62.88 to 51.1 emu/g to 51.1 emu/g with Mg substitution. The photocatalytic study has been carried out with methylene blue dye and exhibits higher efficiency up to 84.5 % of degradation. The synthesized nanoferrite can be an ideal candidate for magnetic storage applications and an efficient photocatalyst.

Structural, microstructural and temperature dependent magnetic properties of Mg–Ni doped CoCr2O4 ceramics

In the present work, [Co(1-(x + y)) MgxNiy][Cr2]O4 (CMNCr)(where, x = y = 0, 0.10, 0.20) NPs are examine in detail by using experimental results. Solution combustion method is adopted to prepare the CMNCr NPs. Experimental results were studied to understand structure (using XRD), microstructure (using SEM) and magnetic behaviour (using SQUID). The structural analysis was confirmed a single-phase spinel cubic structure with singular structural distortions associated with Mg–Ni doping and the generation of metal vacancies. SEM micrographs of all samples reveal their highly porous nature. EDS was utilized to examine the elemental analysis of the samples. The formation of spinel cubic structure without impurity were also confirmed by Fourier-transform infrared (FTIR) spectroscopy and the same tool is used to investigate the absorption bands related to the A-site and B-site. For all samples, paramagnetic phase to ferrimagnetic phase transition observed at TC and conical spiral spin order transition observed at TS. The curie temperature is found to be 98 K, 89 K, and 85 K for [Co][Cr2]O4, [Co0.8 Mg0.1Ni0.1][Cr2]O4 and [Co0.6 Mg0.2Ni0.2][Cr2]O4 samples, respectively. The spiral transition temperature is found to be 26 K, 14 K and 8 K for [Co][Cr2]O4, [Co0.8 Mg0.1Ni0.1][Cr2]O4 and [Co0.6 Mg0.2Ni0.2][Cr2]O4 samples, respectively. All of the samples exhibit paramagnetic behaviour above TC. The negative magnetization effect were observed in [Co0.6 Mg0.2Ni0.2][Cr2]O4 NPs. 20% of Mg and 20% of Ni substitution to Co site in [Co][Cr2]O4 leads to the evident magnetization reversal at the compensation temperature with an applied magnetic field of 100 Oe. The M − H loop at 10 K exhibits large coercivity due to the spiral spin ordering. This phenomenon of negative magnetization in the material results in a stable state of magnetization in the material, which has significant applications in the field of magnetic storage devices.

Influence of La3+ ions doping on morphology and magnetic properties of Mg–Co ferrites

Influence of La3+ ions doping on morphology and magnetic properties of Mg–Co ferrites

Study of physical and magnetic properties of Mg:Co3O4 spinels using L-Arginine as fuel

Magnesium doped cobalt oxide nanoparticles were synthesized via microwave assisted combustion method (MACM). The X-ray diffraction (XRD) patterns of pure Co3O4 and Mg2+ doped Co3O4(x = 0.1 and 0.3) confirmed the cubic spinel structure and without any additional impurity peaks. However, doping Mg2+ concentration, x = 0.3 and 0.5 sample was occur a new hexagonal phase, while the average crystallite size of the cubic spinel structure in the range from 48.5 nm to 15.5 nm. The FT-IR bands at 661 and 573 cm−1 are attributed to the Co–Ostretching mode of cubic spinel Co3O4 structure. The band gap calculated using Kubelka–Munk (K–M) technique and increasedband gap values withthe increase in Mg2+ content (1.87–3.60 eV), due to the causes of sub-bands in the energy band gap. The morphological study revealed the prepared samples exhibited intragranular pores and merged grains with discrete grain boundaries.Magnetization analysis revealed the appearance of para-/superpara- magnetic behavior at ±15KOe.

Influence of different complexing agents on structural, morphological, and magnetic properties of Mg–Co ferrites synthesized by sol–gel auto-combustion method

In the preparation process of magnesium-cobalt nano-ferrite powder (Mg0.1Co0.9Fe2O4) by sol–gel self-propagation method, the effect of complexing agent on the nanostructure and magnetic properties of ferrite is studied by changing the type of complexing agent (the complexing agent includes citric acid, oxalic acid, tartaric acid, glucose, and egg white). The XRD pattern of each sample has eight distinct characteristic peaks, and the number of the strongest peak in each map is one [i.e., (311) peak]. All these evidences can preliminarily indicate that the sample has a spinel structure. In addition, in the FTIR of the sample, it can be seen that there are several distinct characteristic peaks at 580 cm−1 (i.e., Fe–O peak, etc.) which can also prove the structural characteristics of the sample. In the SEM map, the sample can be seen to have an elliptical shape with a crystalline grain size between 28 and 50 nm. From this, we can guess that the complexing agent participates in the reaction and has a certain influence on the particle size of the sample. Elemental analysis showed that all the six samples prepared contained magnesium, cobalt, iron, and oxygen, and then we quantitatively analyzed the sample to find that the prepared sample was the target product. The BET test shows that a sample is prepared with glucose as the complexing agent, the specific surface area of it can be increased. The VSM data show that magnesium–cobalt ferrite powder with high saturation magnetization, residual magnetization, and coercivity can be prepared by selecting glucose as the complexing agent.

Influence of Ho3+ substitution on structural and magnetic properties of Mg–Mn ferrites

Influence of Ho3+ substitution on structural and magnetic properties of Mg–Mn ferrites

Fabrication and Magnetic Properties of Mg and BaFe12O19 Ferromagnetic Composite Powders by Mechanical Alloying

Fabrication and Magnetic Properties of Mg and BaFe12O19 Ferromagnetic Composite Powders by Mechanical Alloying

Analysis of magnesium ferrite and nickel doped magnesium ferrite thin films grown by Spray Pyrolysis

The magnetic magnesium ferrite (MgFe2O4) with a partially inverse spinel structure has been prepared by the classic ceramic method, which have practical application in information storage systems, magnetocaloric refrigeration and magnetic diagnostics. Nickel-magnesium ferrites (Ni:MgxFe3-xO4 or Mg(1-x)NixFe2O4; 0 ≤ x < 1) are magnetic materials of technological significance due to low electrical conductivity, low magnetic coercivity and low eddy current deceives. Magnesium plays an important role in the electrical and magnetic properties of Mg(1-x)NixFe2O4. Thin films were synthesized on different substrates with Spray Pyrolysis (SP) technique. The thin films were analyzed through Atomic Force Microscopy (AFM), X-ray Diffraction (XRD) and UV–Vis double beam spectrophotometer and for magnetic properties of films were used Vibrating-sample magnetometer (VSM) technique. In this study, the film is doped with material having magnetic properties and non-magnetic material. The change in the magnetic properties of the film will be examined as a result of the doping. As a result, the magnetic hysteresis curve of the film was changed by doping. Investigation of magnetic properties is very important for magnetic device applications such as magnetic recording, in magnetic sensor technology and room temperature giant magnetoresistance (GMR) applications.

Influences of La3+ ion substitution on dielectric, susceptibility and permeability properties of Mg–Zn ferrite nanoparticles

Nanoparticles of lanthanum-substituted magnesium zinc ferrites with general formula Mg0.6Zn0.4La2yFe2−2yO4 (where y = 0.0, 0.05, 0.1, 0.15, 0.20 and 0.25) were prepared by employing co-precipitation (wet chemical) method. Phase formation was evaluated by X-ray diffraction analysis. Scanning electron microscopic analysis revealed interlocked nanoparticles exhibiting grain size varies between 300 and 95 nm. Initial permeability (µi) and Curie temperature (TC) decrease with lanthanum content. The synthesized lanthanum-substituted Mg–Zn ferrite nanoparticles displayed single-domain ferromagnetic behaviour below Curie temperature TC and superparamagnetic cluster above TC. The effects of lanthanum substitution on structural, electrical and magnetic properties of Mg–Zn ferrites were studied. The present investigation revealed that lanthanum substitution and content have great influence on the structural, electrical and magnetic properties of Mg–Zn ferrites.

First-Principles Investigation of the Structural, Electronic and Magnetic Properties of α-, β- and γ-Mg(AlH4)2 Complex Hydride

The structural, electronic and magnetic properties of Mg(AlH4)2 in its pressure-induced α-, β- and γ-phases are extensively studied by employing first-principles method within the framework of density functional theory (DFT). This system undergoes a transition from α- to β- and then β- to γ-phase at 0.67 and 10.28 GPa respectively. A slight structural distortion is detected across α- to β-transition due to a small tilting of AlH4 tetrahedron along the c-axis. In the β- to γ-transition, the crystal structure of Mg(AlH4)2 changes markedly. The coordination number of H with Al and Mg increases significantly, which is responsible for the instability of the AlH4 tetrahedron. The drastic change in the structure would originate from the higher coordination number and much more tilting of AlH4 tetrahedron. Alternative long-short/short-long Al-Mg double chains are observed in the c-direction for α- and β-Mg(AlH4)2 but no such double chain is observed in the γ-phase of Mg(AlH4)2. The electronic properties of Mg(AlH4)2 in all phases are predominated by the Al-2p and H-1s orbitals. The ground state properties remain almost similar for both α- and β-phases. The hybridizations of H-1s orbitals with Al-2p and 3s orbitals invoke highly ionic covalent bonding of H and Al within the AlH4− anion complex that is responsible for the non-magnetic nature of α-, β- and γ-Mg(AlH4)2. The volume reduction in the β- and γ-Mg(AlH4)2 phases causes broadening of p bandwidths, which is crucial for the decrease in the band gaps.

Yttrium-substituted Mg–Zn ferrites: correlation of physical properties with Yttrium content

Yttrium- (Y) substituted Mg–Zn ferrites with the compositions of Mg0.5Zn0.5YxFe2−xO4 (0 ≤ x ≤ 0.05) have been synthesized by conventional standard ceramic technique. The effect of Y3+ substitution on the structural, electrical, dielectric and magnetic properties of Mg–Zn ferrites has been studied. The single phase of spinel structure with a very tiny secondary phase of YFeO3 for higher Y contents has been detected. The theoretically estimated lattice constant has been compared with measured experimental lattice constant. The bulk density, X-ray density and porosity have been calculated. The Energy Dispersive X-ray Spectroscopy (EDS) study confirms the presence of Mg, Zn, Y, Fe and O ions in the prepared samples. Frequency dependence of conductivity has been studied and an increase in resistivity (an order) has been observed. Frequency dependence of dielectric constant ( $$\varepsilon$$ ), dielectric loss tangent ( $$\tan \delta$$ ) has been studied and the lowering of $$\varepsilon$$ with the increase of Y content was noted. Dielectric relaxation time was found to vary between 15 to 31 ns. The saturation magnetization (Ms), coercive field (Hc), remanent magnetization (Mr) and Bohr magneton (µB) have been calculated. The variation of Ms has been successfully explained with the variation of A–B interaction strength due to Y substitution. The soft ferromagnetic nature also confirmed from the values of Hc. The complex permeability has been studied and the initial permeability was found to increase with Y up to x = 0.01, thereafter it decreases. The values of electrical resistivity and dielectric constant with proper magnetic properties suggest the suitability of Y-substituted Mg–Zn ferrites in microwave device applications.

Effect of Cation Distribution on the Structural and Magnetic Properties of Mg Substituted Nanosized Manganese Ferrites

In the present investigation, A series of Mg-Mn ferrite nanopowders with composition MgxMn[Formula: see text]Fe2O4 (with [Formula: see text], 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by the co-precipitation method. Thereafter, the obtained powders were pressed separately to form pellets, and sintered at 1250∘C for 3[Formula: see text]h at air atmosphere. Finally, the samples were characterized by X-ray Diffraction (XRD) technique, Scanning Transmission Electron Microscopy (STEM), Alternating Gradient Force Magnetometer (AGFM) and Curie temperature measuring instrument. The lattice constant and distribution of cation in the tetrahedral and octahedral sites have been deduced through XRD data analysis. The XRD pattern confirmed the existence of single phase of cubic spinel crystal structure with the lattice parameter ranging from 8.49 Å (for MnFe2O4) to 8.35 Å (for MgFe2O4). This behavior was attributed to the ionic radii. STEM micrographs exhibit that the particles are spherically shaped and agglomerated with particle size ranging 50–90[Formula: see text]nm quite consistent with particle size obtained from XRD data. The average crystallite size was 70[Formula: see text]nm. Magnetization decreases with increasing Mg concentration except for [Formula: see text], where it shows increasing trend. Curie temperature measurements exhibit increasing trend with increase in magnesium content. The variation of the saturation magnetization and Curie temperature with increasing concentration of the Mg[Formula: see text] ions can be explained on the basis of cation distribution, strengthening A–B interaction and Neel’s two sub-lattice.

Impedance spectroscopy and magnetic properties of Mg doped Y-type barium hexaferrite

Single phase samples of Mg doped Y-type hexaferrites with a composition of Ba2(Co1−xMgx)2Fe12O22 for x = 0–0.5 were prepared using the solid state route. The values of lattice constant and the unit cell volume are found to decrease systematically with increase in Mg concentration. The analysis of impedance spectra and the thermal activation of relaxation process show the contributions from both grains and grain boundaries with decrease in activation energies as Mg concentration is increased. The complex impedance spectra show a deviation from an ideal Debye type and they are modelled using an equivalent circuit consisting of resistances of grains and grain boundaries, grain capacitance and a constant phase element. However at higher temperature (T ≥ 573 K), the contribution of electrode resistance is also taken into account. The analysis of electrical conductivity data show that it is controlled by small polaron tunneling model. The magnetization measurements show that the saturation magnetization marginally decreases from 26.6 emu/g for x = 0–22.7 emu/g for x = 0.5 along with decrease in ferrimagnetic transition temperature from 613 to 581 K.