High Saturation Magnetization Value Research Articles

Structural, dielectric, optical and magnetic studies of dysprosium doped iron oxide nanostructures

Lanthanide-doped iron oxide nanomaterials are potential candidates of current interest for many advanced applications. In this paper, we report on the synthesis of pure and dysprosium (Dy3+) ion doped iron oxide nanostructures, such as ⍺-DyxFe2-xO3 by employing a sol-gel auto combustion method. The pure and doped iron oxide nanostructures have been characterized by employing X-ray diffraction (XRD), transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. The synthesized nanostructures were studied for dielectric, optical and magnetic properties. Dy3+ ion doped ⍺-Fe2O3 nanostructures shows enhancement in the dielectric properties as compared to pure ⍺-Fe2O3. Temperature-dependent conductivity follows Motts law, which confirms the mechanism of variable range hopping in them. Band gap and photoluminescence increases with increase in concentration of Dy3+ ion doping in ⍺-Fe2O3 system. Saturation magnetization increases significantly in doped systems. It was observed that doped systems saturate at low fields (10 kOe) as compared to pure ⍺-Fe2O3 system, which does not saturate up to the maximum applied field (20 kOe). High value of saturation magnetization at low applied magnetic fields, large band gap, enhanced dielectric and efficient photoluminescent properties makes the Dy3+ ion doped iron oxide nanostructures possibly the potential candidates for device applications.

Enhanced magnetic and dielectric properties of NiFe2O4 ferrite ceramics co-substituted by (Li1+, Zn2+ and La3+)

(Li1+, Zn2+ and La3+) co-substituted NiFe2O4 ferrite ceramics (Ni0.8-xZnxLi0.1La0.1Fe2O4, x = 0.0, 0.2, 0.4, 0.6, 0.8) were prepared by the sol-gel auto-combustion method. The structural properties were investigated by X-ray diffraction and field emission scanning electronic microscope techniques. Vibrating sample magnetometer and LCR meter were used to probe magnetic and dielectric properties. A relatively high value of saturation magnetization (105.94 emu/g) can be achieved in Ni0.4Zn0.4Li0.1La0.1Fe2O4 sample sintered at 1100 °C. In addition, the soft magnetic properties are also enhanced due to a reduced coercivity value. Also, dielectric behavior is improved and all the results show that co-substitution with Li1+, Zn2+ and La3+ ions as well as modulation via Zn2+ ions has a great impact on the properties of Ni ferrites.

МАГНИТНЫЕ ХАРАКТЕРИСТИКИ МЕТАМОРФИЗОВАННЫХ УЛЬТРАБАЗИТОВ ОКЕАНИЧЕСКОЙ ЛИТОСФЕРЫ И ОФИОЛИТОВЫХ КОМПЛЕКСОВ

As part of the study of the nature of magnetic anomalies associated with the deep layers of the oceanic crust, a comparative analysis was made of the petromagnetic characteristics of serpentinized mantle ultrabasic samples taken from oceanographic expeditions of the Institute of Oceanology and the Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences in various morphotectonic regions of the World Ocean. The purpose of the work is to obtain information on the composition, concentration, crystallization temperature and structural features of ferromagnetic minerals, which are formed in different conditions of the post-magmatic metamorphism of ultrabasites. Sample collections are divided into three groups. 1. Oceanic peridotites from the rift zones of the mid-ocean ridges and transform faults. 2. Peridotites of the submarine ridge Gorringe, located within the Azoro-Gibraltar zone of faults. 3. Dunites of the Pekulney complex (Chukotka) formed in the island arc system. It has been established that in all selected regions, samples of serpentinized hyperbasites have high values of natural residual magnetization, magnetic susceptibility and saturation magnetization. The highest values of magnetic parameters are the dunites of the Pekulney complex. Estimation of the dependence of the concentration of ferrimagnetic materials C% of the degree of serpentinization of the SS%. showed that it is practically of little significance. The main factors contributing to the increase in the concentration of magnetite are the increased iron content of olivine in ultrabasites and the temperature of metamorphism. The question of the period of formation of magnetites and the stability of their primary residual magnetization requires further study.

Hierarchically Nanostructured Fe₃O₄/C Composite as a Promising Magnetic Targeted Drug Nanocarrier.

Nanostructured Fe₃O₄/C composites are very attractive for high-performance magnetic targeted drug carriers. Herein, Fe₃O₄/C composite nanospheres with good dispersity are prepared by a simple one-step hydrothermal synthesis and subsequent heat treatment in Ar. The composite nanospheres consist of clustered primary nanoparticles, and exhibit a hierarchical architecture with a high specific surface area of 119.3 m² g-1. The Fe₃O₄/C composite nanospheres show a high saturation magnetization value of 101 emu g-1 and good biocompatibility. In particular, the composite nanospheres deliver a large loading content (85.8%) of epirubicin hydrochloride (EPI), resulting from their unique composition and microstructure. More importantly, the release of EPI from the EPI-loaded magnetic carrier (Fe₃O₄/C-EPI) may be enhanced by both a slightly acidic environment and a rotating magnetic field induced by a simple motor-driven magnet system. The above favorable properties make the hierarchical Fe₃O₄/C composite sample a promising candidate for magnetic targeting nanocarriers of EPI.

Selective electrochemical determination of casein based on magnetic molecularly imprinted nanoparticles

The selective electrochemical determination of casein from bovine milk (consisting of α-s1 Casein, α-s2 Casein, β-Casein, and κ-Casein) was developed based on magnetic molecularly imprinted nanoparticles (MMIPs) modified on the carbon paste electrode. Superparamagnetic iron oxide nanoparticles especially magnetite (Fe3O4) have been great potential in environment and biomedical applications. In addition, it holds attractive properties for electrochemical because it facilitates the creation of complex structures for electrode modification. The magnetite resulted from the solvothermal method of Fe(II) and Fe(III) was modified and observed the particle size about 6–10 nm, which confirmed by TEM image and XRD spectrum. Synthesized magnetite has high values of saturation magnetization as 57.766 emu/g and negligible values of remanence and coercivity. The surface modification of magnetite was applied using methyl methacrylate to create surface specificity or molecular imprinting to casein template. The template-shaped cavities coated on magnetic nanoparticles were obtained when the template was removed by porogenic solvent and characterized by FTIR and SEM. Cyclic voltammetry method was examined the casein specific MMIPs electrode. The casein detection was presented high selectivity for casein in cow’s milk. The fabricated electrode has high sensitivity and low limit of detection as 1.058 × 102 µAg−1 mL and 0.048% w/v, respectively. That can be applied to portable device for milk allergen contamination.

Development of Superparamagnetic Nanoparticles Coated with Polyacrylic Acid and Aluminum Hydroxide as an Efficient Contrast Agent for Multimodal Imaging.

Early diagnosis of disease and follow-up of therapy is of vital importance for appropriate patient management since it allows rapid treatment, thereby reducing mortality and improving health and quality of life with lower expenditure for health care systems. New approaches include nanomedicine-based diagnosis combined with therapy. Nanoparticles (NPs), as contrast agents for in vivo diagnosis, have the advantage of combining several imaging agents that are visible using different modalities, thereby achieving high spatial resolution, high sensitivity, high specificity, morphological, and functional information. In this work, we present the development of aluminum hydroxide nanostructures embedded with polyacrylic acid (PAA) coated iron oxide superparamagnetic nanoparticles, Fe3O4@Al(OH)3, synthesized by a two-step co-precipitation and forced hydrolysis method, their physicochemical characterization and first biomedical studies as dual magnetic resonance imaging (MRI)/positron emission tomography (PET) contrast agents for cell imaging. The so-prepared NPs are size-controlled, with diameters below 250 nm, completely and homogeneously coated with an Al(OH)3 phase over the magnetite cores, superparamagnetic with high saturation magnetization value (Ms = 63 emu/g-Fe3O4), and porous at the surface with a chemical affinity for fluoride ion adsorption. The suitability as MRI and PET contrast agents was tested showing high transversal relaxivity (r2) (83.6 mM−1 s−1) and rapid uptake of 18F-labeled fluoride ions as a PET tracer. The loading stability with 18F-fluoride was tested in longitudinal experiments using water, buffer, and cell culture media. Even though the stability of the 18F-label varied, it remained stable under all conditions. A first in vivo experiment indicates the suitability of Fe3O4@Al(OH)3 nanoparticles as a dual contrast agent for sensitive short-term (PET) and high-resolution long-term imaging (MRI).

Fe–Ga alloy based magnetorheological fluid and its viscoelastic characteristics

Flake-like Galfenol particles were fabricated by a conventional rolling and texture annealing process and adopted as the magnetorheological (MR) particle. The flake morphology and crystalline structure were scrutinized using scanning electron microscope and X-ray diffraction, respectively. The Galfenol particles had a high saturation magnetization value of 174emu/g and a Galfenol particle-based MR suspension exhibited typical MR characteristics under input magnetic field strengths. While its shear stress curves are fitted well using the Bingham model, its storage moduli showed a stable plateau area for whole angular frequencies, suggesting distinguished solid-like behavior of the MR fluid.

Hyperthermia, Cytotoxicity, and Cellular Uptake Properties of Manganese and Zinc Ferrite Magnetic Nanoparticles Synthesized by a Polyol-Mediated Process.

Manganese and zinc ferrite magnetic nanoparticles (MNPs) were successfully synthesized using the polyol method in ethylene glycol and were found to have high saturation magnetization values (90–95 emu/g at 4 K) when formed by ~30-nm crystallites assembled in an ~80-nm multicore structure. Hyperthermia data revealed a sigmoidal dependence of the specific absorption rate (SAR) on the alternating magnetic field (AMF) amplitude, with remarkable saturation SAR values in water of ~1200 W/gFe+Mn and ~800 W/gFe+Zn for the Mn and Zn ferrites, respectively. The immobilization of the MNPs in a solid matrix reduced the maximum SAR values by ~300 W/gFe+Mn, Zn for both ferrites. The alignment of the MNPs in a uniform static magnetic field, before their immobilization in a solid matrix, significantly increased their heating performance. Toxicity assays performed in four cell lines revealed a lower toxicity for the Mn ferrites, while in the case of the Zn ferrites, only ~50% of cells were viable upon their incubation for 24 h with 0.2 mg/mL of MNPs. Cellular uptake experiments revealed that both MNPs entered the cells in a time-dependent manner, as they were found initially in endosomes and later in the cytosol. All of the studied cell lines were more sensitive to the ZnFe2O4 MNPs.

Efficient oil removal from wastewater based on polymer coated superhydrophobic tetrapodal magnetic nanocomposite adsorbent

We report the synthesis of an effective, biocompatible, magnetic nanosorbent polydimethylsiloxane@zinc oxide tetrapod@iron oxide nanorod nanohybrid using a hydrothermal process. The synthesized nanohybrid has been applied as a magnetic nanosorbent for oil removal from wastewater. The structural, chemical and magnetic characterizations of synthesized nanohybrid have been performed using X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis and magnetization measurements using a superconducting quantum interference device. The prepared nanohybrid consists of ZnO tetrapods that are coated on the surface by Fe2O3 nanorods. The as-synthesized nanohybrid exhibits an exceptional adsorption ability and considerable magnetic separation due to its large surface area and high magnetic saturation value. The mechanism for the oil adsorption has been explicated by exploring different adsorption kinetics and isotherms models. It is inferred that this magnetic nanosorbent can be employed for effective oil removal from oily wastewater.

Optimizing the physical properties of cobalt/graphene nanocomposites for technological applications

Cobalt nanoferrites with formula CoFe2O4, and CoFe2O4/GR were synthesized using a citrate auto-combustion method. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy (SEM) and the Fourier-transform infrared (FTIR) spectroscopy. The dependence of structure, magnetic and optical properties of cobalt/graphene nanocomposites on the graphene content was studied. The obtained data show that the CoFe2O4 nanoparticles are homogenously decorated on the graphene layers, which act as magnetically inactive layers in turn affecting the magnetization. The high coercivity Hc values reflect that CoFe2O4/GR nanocomposites are hard magnets at room temperature. The energy band gap of the cobalt/graphene is estimated using Kubelka–Munk equation. The energy gap of the investigated nanocomposites was found about 1.4 eV for direct transition. The samples with high saturation magnetization values can affect by the external magnetic field, which is favorable to their application in high adsorption capacity.

Ultrahigh sorption and reduction of Cr(VI) by two novel core-shell composites combined with Fe3O4 and MoS2.

In this investigation, two novel magnetic core-shell Fe3O4@MoS2 (F@M) and MoS2@Fe3O4 (M@F) composites were synthesized and exploited for Cr(VI) elimination. Eco-friendly preparation methods were applied for the synthesis of Fe3O4 and MoS2 composites. The experimental results showed that both F@M and M@F have high saturation magnetization values (43.2 emu/g for F@M and 49.9 emu/g for M@F), excellent maximum sorption capacities of Cr(VI) at pH 5.0 and 298 K (324.3 mg/g for F@M, 290.2 mg/g for M@F), remarkable Cr(VI) removal efficiencies (Cr(VI) sorption equilibrium by both F@M and M@F can be reached in 90 min) and nice regeneration properties (the sorption capabilities of F@M and M@F decreased slightly after five consecutive sorption/desorption cycles). Chemical reduction of Cr(VI) to Cr(III) occurred on the surface of F@M and M@F, and the synergetic reduction of sulfur and ferrous ions made F@M an outstanding material for Cr(VI) removal. This paper highlights F@M and M@F as potential, eco-friendly and ultrahigh-efficiency materials for Cr(VI) pollution cleanup.

Fabrication of a dual T1 and T2 contrast agent for magnetic resonance imaging using cellulose nanocrystals/Fe3O4 nanocomposite

A dual T1-T2 contrast agent for magnetic resonance imaging was developed based on ultrasmall superparamagnetic Fe3O4 nanoparticles. The magnetite nanoparticles were synthesized with thermal decomposition method, then loaded on hydrophilic cellulose nanocrystals-poly citric acid nanoplatform. The high saturation magnetization value (52.2 emu g−1), considerable relaxivity parameters r1 (13.8 mM−1 s−1), r2 (96.2 mM−1 s−1), and appropriate r2/r1 (7.0) at 3.0 T demonstrated the significant enhancement effect of nanocomposite as a dual positive and negative contrast agent. In vitro cellular uptake study using inductively coupled plasma optical emission spectroscopy, in vitro cytotoxicity up to 200 μg mL−1 Fe with HeLa cell lines and colloidal stability investigations revealed that the sufficient cellular uptake, excellent biocompatibility and low toxicity of nanocomposite which is promising for its biomedical applications.

Experimental and theoretical evidences that atomic disorder suppresses half-metallicity of Heusler compounds

Half-metallic compounds present two spin bands with contrasting behaviors, resulting in 100% of spin polarization at the Fermi level; property of crucial importance for applications in spintronic devices. Materials presenting this characteristic are, for instance, some Heusler compounds, mainly Co2-based compounds, which have interesting properties, such as TC above 1000 K and high values of saturation magnetization. However, atomic disorder can affect the half-metallic properties of these materials, decreasing their potential application in spintronic devices. Our aim is to evaluate the role played by atomic disorder in Co2FeSi, which has a Curie temperature of 1100 K and saturation magnetization close to 6 μB. In order to experimentally probe the effects of atomic disorder in this material, samples were subjected to different annealing times, with a subsequent quantification of the disorder degree by means of anomalous X-ray diffraction (AXRD) and Mössbauer spectroscopy. In addition, DFT calculations were performed to provide information on the density of states (DoS) at the Fermi energy under those disorder conditions. This work reveals how disorder plays an important role on the thermodynamic and electronic properties of half-metallic Heusler compounds.

Enhanced multiferroic, magnetodielectric and electrical properties of Sm doped Lanthanum ferrite nanoparticles

In this work, we observe an enhancement of multiferroic property correlated with magnetic, magnetodielectric and ferroelectric properties in lanthanum ferrite (LaFeO3) nanoparticles by virtue of Samarium (Sm) doping in La site. The pure and doped lanthanum ferrite nanoparticle was synthesized by a simple solgel auto combustion route. We observe the positive magnetodielectric coupling in the samples and maximum 0.9% enhancement at the 1 T field in 10% Sm doped LaFeO3 nanoparticles. Highest value of saturation magnetization (1.84 emu/gm) is achieved in Sm doped LaFeO3 system. Particle size is decreased from 58 nm to 44 nm because of doping which is confirmed by transmission electron microscopy (TEM). The purity and nanocrystallinity nature of the prepared samples are confirmed by X-ray diffraction spectroscopy (XRD) pattern. DC and AC conduction mechanism and charge transport mechanism are illustrated in association with Mott’s variable range hopping (VRH) model and correlated barrier hopping (CBH) model respectively. The resistivity (DC & AC) is increased with a markable amount by virtue of Sm substitution. An improvement of dielectric properties is observed where dielectric loss is reduced due to the reduction of oxygen vacancies. The enhancement of magnetic properties is attributed to smaller crystallite size, inhomogeneous and disorder magnetic spin. The Sm doped LaFeO3 has been presented here which has promising applications in spintronic devices.

Controlled synthesis of iron oxide NPs derived from conventionally and ultrasonically prepared iron(III) coordination polymer: Potential remediation and catalytic degradation of methylene blue

Coordination polymers acquired much interest due to their powerful applications. Herein, coordination polymer of the formula {[Fe(PZDC)Cl(H2O)2]}n has been prepared conventionally and ultrasonically. The structure was investigated using elemental analysis, IR and X-ray diffraction (XRD). The ultrasonic-assisted synthesis steers the formation of the crystalline coordination polymer while the conventional method leads to the amorphous phase. Calcination of the synthesized coordination polymers was made in glass tubes (length = 200 mm and width = 15 mm) under air at variable temperatures. Depending on the calcination conditions, different iron oxide phases/polymorphs were produced. Maghemite; γ-Fe2O3 was formed by heat-treatment at 350 °C for 1 h regardless of the synthesis way of the precursor. X-ray single phase of hematite; α-Fe2O3 was obtained by calcination of the conventionally prepared precursor at 450 °C for 1 h. Nitrogen adsorption-desorption isotherms showed that, the specific surface areas of the γ-Fe2O3 (conventionally produced precursor), γ-Fe2O3 (ultrasonically formed precursor) and α-Fe2O3 are 125, 132 and 30.5 m2g-1, respectively. Magnetic measurements showed that the best properties are exhibited by γ-Fe2O3 NPs synthesized from the conventionally prepared precursor; highest values of saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) are obtained. On the other hand α-Fe2O3 showed the lowest magnetic properties. The activity of prepared coordination polymers and iron oxide phases for removal of methylene blue (MB) was tested. γ-Fe2O3 (conventionally formed precursor) showed the highest adsorption efficiency (∼22%). On the other side, the coordination polymer (conventionally prepared) exhibited the best removal efficiency of methylene blue in a Fenton-like process. Degradation efficiency of 97.2% was achieved in a very short time (15 min).

Synthesis of PVP Coated Superparamagnetic Iron Oxide Nanoparticles with a High Saturation Magnetization

Superparamagnetic iron oxide nanoparticles (SPION) were synthesized by one pot coprecipitation method at room temperature in the presence of Polyvinylpyrrolidone (PVP). X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Vibrating Sample Magnetometer (VSM) were used to analysis the physicochemical properties of PVP-SPION. The XRD patterns confirmed that the structure of as-synthesized sample is magnetite with cubic structure system. In TEM results, the image of PVP-SPION displayed that the size of particles was 14.05 nm with narrower size distribution and also the PVP played important role to minimize the agglomeration of SPION. Finally, the high saturation magnetization value of PVP-SPION (53.0 emu/g) indicate the as-synthesized sample has a great potential as a contrast agent for MRI.

Improvement in magnetic parameters of polycrystalline barium hexaferrite by nonmagnetic cation substitution and microwave processing

Polycrystalline ZnZr substituted barium hexaferrite (BaFe12-xZnx/2Zrx/2O19 where x = 0.3, 0.5, 0.7 and 1.0) specimen have been synthesized by two different methods, namely conventional and microwave sintering. The latter has resulted in magnetoplumbite phase in 5 min at a lower temperature (1000 °C). The values of magnetic parameters of different samples are extracted from the corresponding M − H loops using law of approach to saturation magnetization. A high value of saturation magnetization (Ms = 76 emu/g) is obtained for a conventionally sintered sample. Still higher value of saturation magnetization (Ms = 104 emu/g) has been obtained for the microwave sintered cation substituted sample. The increase in the magnetization has been attributed to the magnetic reordering of iron cations in the non-magnetic Zn2+-Zr4+ substituted samples. The coercivity of the microwave processed substituted samples has been drastically reduced to 163 Oe (from 2961 Oe for conventionally sintered pristine sample). The observed decrement can be ascribed to the increase in particle size and reduction in magnetocrystalline anisotropy (2.58 × 106 erg/cc). Raman spectra of the substituted samples have shown a shift in the vibrational frequencies (characteristic of magnetoplumbite phase) with cation substitution. This suggests that the non-magnetic ZnZr cations replace Fe3+ from certain interstitial sites (4f1, 4f2, 2b and 12k).

Magnetic and microwave absorption properties of FeNi3/NiFe2O4 composites synthesized by solution combustion method

FeNi3/NiFe2O4 composites were prepared by solution combustion synthesis method. The solution combustion process was conducted in a closed system by use of conventional and microwave heating. Phase evolution, microstructure, magnetic and microwave absorption properties were studied by X-ray diffraction, electron microscopy, vibrating sample magnetometry and vector network analyzer techniques. The amount of FeNi3 phase was tuned by heating mode and amount of nickel precursor. The composites with higher amounts of FeNi3 phase and larger sintered particles (0.4–0.8 μm) were synthesized by microwave heating. The highest value of saturation magnetization (81 emu/g) was attained in the NiFe2O4-45 wt % FeNi3 composite. The FeNi3/NiFe2O4 composites had the high permeability due to the high saturation magnetization. The composites synthesized by conventional heating showed the maximum reflection loss of −15 dB in Ku band (12–18 GHz) with the band width of 3.8 GHz.

Formation of magnetically-oriented barium hexaferrite films by aerosol deposition

Abstract We have deposited polycrystalline films of barium hexaferrite utilizing aerosol deposition at room temperature. Magnetic orientation was achieved by using a 4 kOe permanent magnet mounted in close proximity to the substrate during deposition. We find that these films show crystallographic orientation and magnetic anisotropy out of plane corresponding to the {0 0 2 l } diffraction planes. To further explore the film properties we performed sintering treatments up to 1000 °C and found that the magnetic properties are further improved. For these films the magnetic saturation is 3683 G with a squareness value of 0.82. The magnetic and crystallographic texturing indicate 29% grain orientation with a coercivity of 4.6 kOe. These values indicate that the films are of good quality for potential integration into microwave systems that require high values of saturation magnetization, squareness, and coercivity with a good degree of self-bias.

Analysis of Cd2+ and In3+ ions doping on microstructure, optical, magnetic and mo¨ssbauer spectral properties of sol-gel synthesized BaM hexagonal ferrite based nanomaterials

Abstract Precise studies of cadmium and indium doped barium hexagonal ferrites having chemical composition Ba0.7Nd0.3Cdx/2Inx/2Fe12-xO19 (x = 0.0, 0.1, 0.2, 0.3) have been performed by sol-gel auto-combustion method in which ethylene glycol was used as a gel precursor. The structural, morphological, optical, elemental and magnetic properties have been studied by using various techniques like XRD, FESEM, FTIR, EDS and VSM. The XRD patterns shows characteristic (110), (008), (107), (114), (108), (203), (205), (206), (1011), (300), (217), (2011), (220), (2014) peaks along with the presence of secondary phase confirming the formation of hexagonal structure with an average crystallite size of 43–59 nm. FESEM supports the formation of hexagonal, dense and agglomerated nanoparticles. The Vibronic study using infrared radiation was carried by FTIR analysis reveal the various configuration modes with hexagonal symmetry of prepared nanoparticles. The magnetic measurements have been studied at room temperature indicates that saturation magnetization (Ms) and magnetic moment (nB) found to be of range 40–86 emu/g and 7.97–17.23 μB. The precise magnetic studies made it possible to reveal that saturation magnetization (Ms) increases with the cadmium and indium concentration for x = 0.1 and after that it decreases for x = 0.2, 0.3 which may be due to the difference in the magnetic moments of Cd, In and Fe ions. Due to high value of saturation magnetization (Ms), it can be used for applications in the field of high density recording storage devices and also, this magnetic change has been explained on the basis of exchange interactions. The room temperature M o ¨ ssbauer spectra of all the nano-sized materials shows normal Zeeman splitting consisting of six merged line patterns which indicates the formation of ferromagnetic phase that supports the magnetic properties.