Size-dependent Magnetic Properties Research Articles

Size-dependent magnetic properties of Mn–Zn ferrite nanoparticles synthesized by chemical solution method

Size-dependent magnetic properties of Mn–Zn ferrite nanoparticles synthesized by chemical solution method

Investigation of size-dependent electrical, dielectric, and magnetic properties of iron oxide nanostructures

In this article we report magnetite (Fe3O4) nanoparticles prepared via hydrothermal technique at different reaction time and precursor's concentration. X-ray diffraction (XRD) result shows the formation of single phase iron oxide that matches well with standard JCPDS card #: 01-079-0418. Excellent crystallinity was achieved for octahedral shape particles (∼150 nm) as compared to porous spherical shape Fe3O4 particles (∼250 nm) which is supported by field emission scanning electron microscope images (FESEM). Fourier transform infrared spectroscopy (FTIR) results show strong peak at 540 cm−1 for both samples indicating Fe–O–Fe bending vibration and formation of chemical bonding characteristic of Fe3O4 lattice structure. The electrical transport properties show that correlated barrier hopping (CBH) between Fe3+ and Fe2+ ions, is the possible operating conduction mechanism in both samples and octahedral shape Fe3O4 nanoparticles are more conductive than porous spherical shape particles. The corresponding activation energies of grain and grain boundary for octahedral and porous spherical shape Fe3O4 nanoparticles are ∼0.197 & ∼0.292eV and ∼0.226 & ∼0.30eV, respectively. Furthermore, dielectric constant of the octahedral shape Fe3O4 nanoparticles is high due to its low energy losses and high value of crystallinity as compared to spherical shape particles. Magnetic properties show ferrimagnetic nature of both Fe3O4 samples. Corresponding high values of magnetic saturation, coercivity, and remanent magnetization of octahedral shape Fe3O4 particles are 71emu/g, 123 Oe, and 10.6 emu/g, respectively, which indicates the influence of magnetic properties on the grain size, crystallinity and morphology of the constituent particles.

Sensitization Strategies of Lateral Flow Immunochromatography for Gold Modified Nanomaterials in Biosensor Development.

Gold nanomaterials have become very attractive nanomaterials for biomedical research due to their unique physical and chemical properties, including size dependent optical, magnetic and catalytic properties, surface plasmon resonance (SPR), biological affinity and structural suitability. The performance of biosensing and biodiagnosis can be significantly improved in sensitivity, specificity, speed, contrast, resolution and so on by utilizing multiple optical properties of different gold nanostructures. Lateral flow immunochromatographic assay (LFIA) based on gold nanoparticles (GNPs) has the advantages of simple, fast operation, stable technology, and low cost, making it one of the most widely used in vitro diagnostics (IVDs). However, the traditional colloidal gold (CG)-based LFIA can only achieve qualitative or semi-quantitative detection, and its low detection sensitivity cannot meet the current detection needs. Due to the strong dependence of the optical properties of gold nanomaterials on their shape and surface properties, gold-based nanomaterial modification has brought new possibilities to the IVDs: people have attempted to change the morphology and size of gold nanomaterials themselves or hybrid with other elements for application in LFIA. In this paper, many well-designed plasmonic gold nanostructures for further improving the sensitivity and signal output stability of LFIA have been summarized. In addition, some opportunities and challenges that gold-based LFIA may encounter at present or in the future are also mentioned in this paper. In summary, this paper will demonstrate some feasible strategies for the manufacture of potential gold-based nanobiosensors of post of care testing (POCT) for faster detection and more accurate disease diagnosis.

Particle size-dependent structural and magnetic properties of Pr0.6-xBixSr0.4MnO3 (x = 0.10 and 0.25)

Nanoparticles of Pr0.6-xBixSr0.4MnO3 (x = 0.10 and 0.25) have been prepared using the swift and cost-effective top-down approach in a high-energy planetary ball mill without any chemical processing and environmental impacts resulting due to pollutants arising from nanoparticle synthesis. The work investigates the role of particle size reduction on the structural and magnetic properties. An increase in milling time from 0 to 240 min results in the drastic reduction of particle size which drops significantly in the initial phase of ball milling i.e., 0–60 min while the microstrain and dislocation densities show nearly monotonic increase. Interestingly the magnetism and size reduction demonstrate a clear one to one correspondence. In both compositions, the paramagnetic (PM) to ferromagnetic (FM) transition, TC decreases and the magnetic transitions broaden both as function Bi and size reduction. The Curie–Weiss analysis of the inverse magnetic susceptibility ({chi }^{-1}) shows a deviation from linearity indicating the presence of the short-range FM interactions above TC which has been understood as Griffith’s phase like singularity. The size reduction can effectively reduce TC, enabling a significant control over tuning of transition temperature and net magnetization. The field dependent magnetization for x = 0.10 demonstrate dominant FM state whereas for x = 0.25, metamagnetic magnetization highlights competitive coexistence of FM and antiferromagnetic (AFM) interactions in the system. With ball milling, the net magnetization decreases, and the metamagnetic behaviour is suppressed. The M–H loops of ball milled nanoparticles are highly unsaturated indicating the enhanced surface disorder in the nanoparticles which can be understood using the core–shell structure.

Size-Controlled Synthesis of Luminescent Few-Atom Silver Clusters via Electron Transfer in Isostructural Redox-Active Porous Ionic Crystals.

Ag clusters with a controlled number of atoms have received significant interest because they show size-dependent catalytic, optical, electronic, or magnetic properties. However, the synthesis of size-controlled, ligand-free, and air-stable Ag clusters with high yields has not been well-established. Herein, it is shown that isostructural porous ionic crystals (PICs) with redox-active polyoxometalates (POMs) can be used to synthesize Ag clusters via electron transfer from POMs to Ag+ . Ag clusters with average numbers of three, four, or six atoms emitting blue, green, or red colors, respectively, are formed and stabilized in the PICs under ambient conditions without any protecting ligands. The cluster size solely correlates with the degree of electron transfer, which is controlled by the reduction time and types of ions or elements of the PICs. Thus, advantages have been taken of POMs as electron sources and PICs as scaffolds to demonstrate a convenient method to obtain few-atom Ag clusters.

Particles size-dependent magnetic properties of a FeSiAl soft magnetic composite with hybrid insulating coating for MHz applications

In this work, organosilane modified water-soluble silicone resin coated spherical-FeSiAl soft magnetic composites with different particle sizes were prepared, and the effects of the particle size on the permeability, magnetic loss, and DC bias were investigated. For large particles composite, multi-domain lead to the introduction of domain wall resonance, which restricts the permeability in low frequency. As the particle size decreases, the particles tend to be single domain particles resulting in a decrease of the domain wall resonance component and an enhancement of the spin rotation one. Two stages with different loss mechanisms were investigated and the sudden increase of the loss near 70 kHz is ascribed to the short circuit of the insulating coating in high frequency due to the space charge polarization. Furthermore, electrochemical analysis also demonstrates the insulation of this soft magnetic composite. This ultrafine FeSiAl composite may promote the development of MHz frequency semiconductor power devices.

Size-dependent magnetic properties of Mn-Co-NiO based heterostructured nanoparticles

In this work, we investigate the synthesis, along with the structural and magnetic properties, of novel Mn-Co-NiO-based heterostructured nanocrystals (HNCs). The objective is to develop novel, well-structurally ordered inverted antiferromagnetic (AFM) NiO–ferrimagnetic (FiM) spinel phase overgrowth HNCs. Inverted HNCs are particularly promising for magnetic device applications because their magnetic properties are more easily controlled by having well-ordered AFM cores, which can result in magnetic structures having large coercivities, tunable blocking temperatures, and other enhanced magnetic effects. The synthesis of the HNCs is accomplished using a two-step process: In the first step, NiO nanoparticles are synthesized using a thermal decomposition method. Subsequently, Mn-Co overgrowth phases are grown on the NiO nanoparticles via hydrothermal nanophase epitaxy, using a fixed pH level (∼5.3) of the aqueous medium. This pH level was selected based on previous work in our laboratory showing that NiO/Mn3O4 HNCs of constant size have optimal coercivity and exchange bias when synthesized at a pH of 5.0. The crystalline structure and gross morphology of the Mn-Co-NiO-based HNCs have been analyzed using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques, respectively. Analysis using these techniques shows that the HNCs are composed of a NiO core and a CoMn2O4 overgrowth phase. Rietveld refinement of XRD data shows that the NiO core has the rocksalt (Fm3̄m) cubic crystal structure and the CoMn2O4 overgrowth has the spinel (I41/amd) crystal structure. Moreover, an increased relative amount of the CoMn2O4 overgrowth phase is deposited with decreasing NiO core particle size during the synthesis of the HNCs. The results from PPMS magnetization and high-resolution transmission electron microscopy (HRTEM) characterization of the Mn-Co-NiO-based HNCs are discussed herein.

Simultaneous estimation of magnetic moment and Brownian relaxation time distributions of magnetic nanoparticles based on magnetic particle spectroscopy for biosensing application.

Magnetic nanoparticles (MNPs) exhibit unique physicochemical characteristics owing to their comparable dimensions with important biological substances, high surface-to-volume ratios, size-dependent magnetic properties, and temperature sensitivity. In this study, we present a novel method for simultaneously estimating the magnetic moment and Brownian relaxation time distribution of MNPs based on AC magnetization harmonics. We provide a detailed description of the theoretical framework and experimental procedures. The dynamics of MNP magnetization are described using the Fokker-Planck equation, and a matrix equation is established to connect the magnetic moment, Brownian relaxation time, and magnetization harmonics. By employing a non-negative linear least squares algorithm with constraints, the magnetic moment and Brownian relaxation time distributions are inversed, which are then converted into the distributions of core sizes and hydrodynamic sizes. Finally, the estimated core size distribution reconstructed from M-H curves is consistent with the hydrodynamic size distribution measured by dynamic light scattering. This method is particularly useful for facilitating quantitative magnetic immunoassays.

Effect of Sr-Doping on Structural and Magnetic Properties of La1−xSrxMnO3 Nanoparticles

Polycrystalline La[Formula: see text]SrxMnO3 ([Formula: see text]–0.4) lanthanum strontium manganese oxide (LSMO), nanoparticles exhibit interesting size-dependent structural and magnetic properties. LSMO nanoparticles have attracted considerable attention in recent years because of their tunable magnetic properties like intrinsic and extrinsic colossal magnetoresistance, single domain superparamagnetic structure with near room temperature Curie point ([Formula: see text]). They find interesting applications in catalysis, biomedicine and data storage. Properties of LSMO nanoparticles are strongly correlated to extent of Sr-doping at La-site, their particle size and the extent to which different crystallographic phases (rhombohedral/orthorhombic) appear. A major aim of this study is to understand the effect of Sr-doping on the structural and magnetic properties of LSMO nanoparticles synthesized via the sol–gel auto combustion route. Structural and magnetic properties were investigated by powder X-ray diffraction coupled with Rietveld refinement and vibrating sample magnetometer, respectively. Rietveld refinement of diffractograms revealed that irrespective of Sr-doping, LSMO nanoparticles were crystallized in rhombohedral ([Formula: see text]) and orthorhombic (Pbnm) mixed phases. The rhombohedral phase appears to be the dominant crystallographic phase. VSM study revealed that irrespective of Sr-doping LSMO nanoparticles exhibit soft ferromagnetic behavior. With the increase in Sr-doping, saturation magnetization ([Formula: see text]) of LSMO nanoparticles increases, while their Curie temperature remains constant at [Formula: see text][Formula: see text]K. To establish the correlation between structural and magnetic properties of LSMO nanoparticles, [Formula: see text]–[Formula: see text] curves were fitted with modified Langevin function. It was observed that with an increase in Sr-doping, magnetic domain size, polydispersity and saturation magnetization increase. This increase is attributed to the corresponding increase in the rhombohedral phase fraction of LSMO nanoparticles. Thus, through Sr-doping, the magnetic properties of LSMO nanoparticles can be tuned by controlling their crystallographic phase fractions.

Fe3O4 nanoparticles synthesized by one-step reduction with nanoscale size-dependent magnetic properties

Fe3O4 nanoparticles synthesized by one-step reduction with nanoscale size-dependent magnetic properties

Raman study of BiFeO3 nanostructures using different excitation wavelengths: Effects of crystallite size on vibrational modes

Bismuth ferrite (BiFeO3) is a perovskite metal oxide well known because of its multifunctional properties. In this study, we report Raman analysis of BiFeO3 nanostructures synthesized using the sol–gel method at different annealing conditions. The synthesis was conducted at two different annealing temperatures of 500 °C and 600 °C, and three different annealing rates of 2, 5, and 10 °C/min. The crystallite sizes and particle sizes were evaluated for the obtained nanostructures using X-ray diffraction and scanning electron microscopy. Raman scattering study was conducted for the prepared BiFeO3 samples at different excitation wavelengths in the visible and near-infrared region (457 nm, 532 nm, 633 nm, and 785 nm). The variations in the features of the Raman modes with different excitation wavelengths and annealing conditions were examined in detail. Resonant Raman scattering was observed when the excitation energy was comparable to or greater than the bandgaps of the BiFeO3 nanostructures, where the intensities of the A1-3, E-3, and E-4 vibrational modes increased. The variations in the relative intensities and areas of the A1-2 and A1-1 modes with the crystallite size were correlated with the occurrence of size-dependent magnetic properties in BiFeO3.

Temperature assisted size dependent synthesis and magnetic properties of rare-earth chromium oxide nanoparticles

We report the synthesis of homogeneous single-phase nanoparticles of RCrO4 and RCrO3 (R = Sm, Gd, Dy, and Er) compounds using a modified sol–gel hydrothermal method followed by heat treatment. Annealing of the as-prepared powder sample at ambient pressure enables chromium to remain in the metastable Cr5+ (4s03d1) state by crystallizing into a zircon-type tetragonal RCrO4 (S.G. I41/amd, D4h19 symmetry) structure at 773 K, while it chooses to form orthorhombic RCrO3 (S.G. Pbnm, D4h19 symmetry) structure with a stable Cr3+ (4s03d3) state at 973 K. The analysis of DC magnetization (M) versus temperature (T) in an external magnetic field, H = 100 Oe for polycrystalline RCrO4 indicates the magnetic transition temperatures, TC ∼ 20 K. The derivative of zero-field cooled magnetic susceptibility with respect to T, dχZFCdT, versus T, indicates the presence of competing magnetic interactions due to the ferromagnetic (FM) and antiferromagnetic (AFM) ordering of Cr5+ and R3+ in RCrO4 respectively near magnetic transition. This feature specifies magnetic frustration that leads to metamagnetism in RCrO4. The fit of non-linear magnetic susceptibility, χ=MH, to χ=χ0+CT-θ, with a non-zero χ0 determined from high-T data gives effective magnetic moment, μeff, which is in accordance with the theoretical value. The analysis of M vs. T indicates that RCrO3 undergoes a paramagnetic (PM) to canted-antiferromagnetic (CAFM) transition of Cr sublattices at Néel temperature (TNCr) because of antisymmetric Dzyaloshinskii-Moriya (DM) interaction due to Cr–O–Cr superexchange with a possible antiferromagnetic (AFM) ordering of the rare-earth at low temperature (TNR < 20 K). The linear fit of χ-1 vs. T with a zero χ0 shows Curie-Weiss law is more appropriate at T>TC resulting expected μeff values for RCrO3.

Size-Dependent Structural, Magnetic and Magnetothermal Properties of Y3Fe5O12 Fine Particles Obtained by SCS.

Iron-containing oxides are the most important functional substance class and find a tremendous variety of applications. An attractive modern application is their use in biomedical technologies as components in systems for imaging, drug delivery, magnetically mediated hyperthermia, etc. In this paper, we report the results of the experimental investigation of submicron Y3Fe5O12 garnet particles obtained in different sizes by solution combustion synthesis (SCS) using glycine organic fuel to discuss the interdependence of peculiarities of the crystal and magnetic structure and size’s influence on its functional magnetothermal performance. A complex study including Mössbauer and Raman spectroscopy accompanied by X-ray diffractometry, SEM, and measurements of field and temperature magnetic properties were performed. The influence of the size effects and perfectness of structure on the particle set magnetization was revealed. The ranges of different mechanisms of magnetothermal effect in the AC magnetic field were determined.

The Anisotropic Magnetocaloric Effect and Size-Dependent Magnetic Properties of Iron Particles

We present a theoretical study on the anisotropic magnetocaloric effect and the size-dependent magnetic properties of Fe particles of radii in the range 25–150 Å. An observable increase has been found in the magnetization, of the low radii (25–75 Å) particles, by reducing the temperature to 4 K. The anisotropic isothermal change in entropy ΔSm has been calculated by taking the difference between maximum ΔSm along the easy [100] and hard [111] directions. The maximum anisotropic ΔSm is 0.015 J/kg K for a field change of 500 Oe along the [100] direction. The ΔSm temperature dependence exhibits a table-like plateau for small radii (25–75 Å) and in low fields below 300Oe. This enhances the relative cooling power (RCP) of the Fe element to be 8.11 J/kg for particles of 25 Å radius. Also, the calculation of anisotropic ΔTad was performed along the easy axis and showed an increase in the maximum value around 37% relative to the experimental conventional value.

Quenching of spin-orbit coupling and signature of Griffiths Phase in nanocrystalline La0.6Ba0.4MnO3 perovskite manganite

The size-dependent structural and magnetic properties of nano and bulk samples of 40 ​mol% Ba2+-doped LaMnO3 (i.e., La0.6Ba0.4MnO3) manganite have been investigated in detail. The Rietveld refinement of X-ray diffraction data confirms that nano and bulk La0.6Ba0.4MnO3 manganites crystallize into ideal cubic perovskite structure with Pm3¯m space group. The refined unit cell parameters decrease with increasing calcinations temperature or particle size. The temperature dependent magnetization measurements reveal that both the bulk and nano samples exhibit paramagnetic (PM) to ferromagnetic (FM) phase transition at Curie temperature (TC). A distinct bifurcation between magnetization curves under zero-field cooled (MZFC) and field-cooled (MFC) measurements reveals the possible existence of frustrated magnetic ordering or spin glass clusters. For nano sample, a sharp downward deviation in inverse susceptibility from Curie-Weiss law is observed, which indicates the existence of Griffiths Phase. The analysis of the field dependent magnetization M(H) curves measured at 10 ​K, in terms of saturation moments, reveals that there is a coupling between spin and orbital magnetic moments, in bulk sample of La0.6Ba0.4MnO3 manganite, which can be quenched by reducing particle size of the manganite. According to the Banerjee's criterion, nano sample exhibits first-order magnetic transition and bulk sample shows second-order magnetic transition in the low magnetic field region.

Solid-State Preparation of Metal and Metal Oxides Nanostructures and Their Application in Environmental Remediation.

Nanomaterials have attracted much attention over the last decades due to their very different properties compared to those of bulk equivalents, such as a large surface-to-volume ratio, the size-dependent optical, physical, and magnetic properties. A number of solution fabrication methods have been developed for the synthesis of metal and metal oxides nanoparticles, but few solid-state methods have been reported. The application of nanostructured materials to electronic solid-state devices or to high-temperature technology requires, however, adequate solid-state methods for obtaining nanostructured materials. In this review, we discuss some of the main current methods of obtaining nanomaterials in solid state, and also we summarize the obtaining of nanomaterials using a new general method in solid state. This new solid-state method to prepare metals and metallic oxides nanostructures start with the preparation of the macromolecular complexes chitosan·Xn and PS-co-4-PVP·MXn as precursors (X = anion accompanying the cationic metal, n = is the subscript, which indicates the number of anions in the formula of the metal salt and PS-co-4-PVP = poly(styrene-co-4-vinylpyridine)). Then, the solid-state pyrolysis under air and at 800 °C affords nanoparticles of M°, MxOy depending on the nature of the metal. Metallic nanoparticles are obtained for noble metals such as Au, while the respective metal oxide is obtained for transition, representative, and lanthanide metals. Size and morphology depend on the nature of the polymer as well as on the spacing of the metals within the polymeric chain. Noticeably in the case of TiO2, anatase or rutile phases can be tuned by the nature of the Ti salts coordinated in the macromolecular polymer. A mechanism for the formation of nanoparticles is outlined on the basis of TG/DSC data. Some applications such as photocatalytic degradation of methylene by different metal oxides obtained by the presented solid-state method are also described. A brief review of the main solid-state methods to prepare nanoparticles is also outlined in the introduction. Some challenges to further development of these materials and methods are finally discussed.

Particle-size dependent magnetic property variations in the Yangtze delta sediments of late Holocene: Effects of pedogenesis and diagenesis

Late Holocene is a key period for the formation of modern deltas, and environmental magnetism is commonly used to infer paleoenvironmental information. Magnetic properties of bulk sediments are influenced by both hydrodynamic sorting and post-depositional pedogenesis and diagenesis, and the relationship between them is unclear. Detailed magnetic study on particle size fractions is a tool for understanding this issue and has been used in surface sediments, while the applications in delta core sediments are rare. Here we investigated the bulk and particle size dependent magnetic properties of the Yangtze River Delta core sediments over the past 3 ka, to determine the main mechanism for bulk magnetic property changes under the effects of pedogenesis and diagenesis. Our results showed that, in all particle size fractions, pedogenesis occurred in the top ∼2 m (within 0.3 ka) and the dissolution of fine magnetic minerals driven by early diagenesis appeared below this depth and completed at ∼20 m in depth (∼1.5 ka). These effects, including the dissolution of fine-grained ferrimagnetic minerals and the precipitation of authigenic greigite, were most obvious in the <16 μm fraction and decreased with coarsening particle sizes. The grain sizes of magnetic minerals were the finest in the <16 μm sediments and the coarsest in the 32–63 μm sediments, with intermediate similar features observed in the 16–32 and 63–125 μm sediments. Bulk magnetic properties were dominated by the <16 μm sediments. Our findings distinguished the differences between the effects of pedogenesis and early diagenesis among size fractions, which may provide a better approach to recognize redox states and provenance in delta sediments since the late Holocene.

Structural, electronic and magnetic properties of CrmSn and CrmSen nanoflakes: An ab initio investigation

With the investigation of 2D monolayer, there is intensive study on ultra-small sized 1D nanomaterials such as nanoribbons , nanowires and nanoflakes etc. Here we have systematically elucidated the spin-dependent, shape and size dependent structural, electronic and magnetic properties of two transition metal dichalcogenide (TMD) nanoflakes namely: Cr m S n and Cr m Se n using density functional theory . Here we take the triangular and rhombic type configuration of nanoflakes. We found that the structural configuration becomes more stable as we increase the size of the nanoflakes. The HOMO-LUMO gaps increases with the increase in size of nanoflakes. The studied nanoflakes are magnetic semiconductor except two flakes Cr 12 S 20 and Cr 8 S 16 which are spin gapless semiconductors (SGS). So these efforts of nanoscaling helps us to engineer electronic devices at nanoscale . Also our spin dependent findings underscore the importance of TMDs nanoflakes for their future applications in spintronics , optoelectronics etc. • Increase in the size of nanoflakes leads to increase in the cohesive energy, stability and decrease the HOMO-LUMO gap. • All the nanoflakes are magnetic semiconductor except Cr 12 S 20 and Cr 8 S 16 which are spin gapless semiconductors (SGS). • Spin polarization ( P s ) which is proportional to magnetic moment decreases with flake size. • SGS materials and spin polarization with high value of P s are use to fabricate ultrafast and low energy consumption in spintronics and electronic devices.

Thermomagnetic Properties of Metal and Metal-oxide Nanoparticles

Variation of thermomagnetic properties of nanoparticles are the matter of great debate. To develop a suitable model for the study of magnetic properties, the size and shape dependent magnetic properties such as Curie temperature (TC), Neel temperature (TN) and magnetization (MS) of magnetic nanoparticles (Fe, Ni, Co, Fe3O4, NiO, CoO, CuO, Ho and CoFe2O4) have been studied. In the present work, bond energy model has been used with the concept of dangling bond and its effect on the surface of nanoparticles. It is observed that the introduction of packing fraction of materials to this model supports the experimental facts. The obtained results have been explained by considering the concept of dangling bond at the surface of nanoparticle and packing fraction of crystal. It is observed that these magnetic properties decrease with reducing size of nanoparticles and the available experimental data are in good agreement with present theoretical model. The validity of present model encourages us to predict the behaviour of thermomagnetic properties of other nanoparticles.

Effect of Reduced Dimensionality on the Magnetic and Transport Properties of Ca Doped Colossal Magnetoresistive Nanoparticles

Magnetic and electrical measurements of different nanosize Ca doped colossal magnetoresistive La0.7Ca0.3MnO3 are reported. The nanoparticles are synthesized with the modified citrate rout at different temperatures. X-ray diffraction measurements revealed three dominant peaks 23.040, 40.5170 .47.170, 58.660 which confirms the perovskite-like structure. The average crystallite size the nanoparticles are found to be 20 to 32nm. All the synthesized nanoparticles exhibit ferromagnetic ordering close to the phase transition temperatures. The size dependent magnetic and electrical transport properties are explored at different fields and temperature. Saturation magnetization is found to decrease with decreasing particle diameter. It is found that the particle size can tune the trend of coercive field. Coercive field first increases from 78 to 210 Oe and then decreases to 174 Oe. The electrical transition temperature is found to be 158 K for 20nm particle. Oxygen deficiency in such system generally reduces Mn4+ to Mn3+ to keep the charge neutrality of the structure and hence it destroys the conduction path ways to mobile electrons, at least in long range, and thus insulating behavior becomes more prominent in the larger temperature range. The trend at lower temperature attribute to the coulomb blockade.