Splitting Field Research Articles

Magnetic and hyperfine interactions in HoFe1−xCrxO3 (0≤x≤1) compounds

We report on the magnetic and Mössbauer properties of polycrystalline HoFe1-xCrxO3 (0≤x≤1) compounds. Magnetization data reveals the continuous tailoring of magnetic transition due to weakening of Ho3+-Fe3+ and Fe3+-Fe3+ interactions in the entire temperature range by replacing the Fe3+ ions with Cr3+ ions. The observed decrease in Néel temperature (TN) and increase in spin re-orientation transition temperature (TSR) with the replacement of Fe3+ with Cr3+ is ascribed to the weakening of Fe(Cr)-O-Fe(Cr) antiferromagnetic exchange interaction. In addition, we also attribute such a change in TN to the enhancement of ferromagnetic interaction of adjacent Cr3+ moments through t-e hybridization as a result of the structural distortion. The decrease in isomer shift (IS) suggests enhancement of the interaction between nuclear charge with the 3s electrons as a result of decrease in radial part of 3d wave function with Cr addition. In this paper we also discuss about the variation of quadrupole splitting (QS) and hyperfine fields (Hhf) with Cr addition in HoFe1-xCrxO3 (0≤x≤1) compounds.

Synthesis and Structural and Magnetic Characterization of BaZn x Fe12−x O19 Hexaferrite: Hyperfine Interactions

To study the effect of Zn substitution on structural magnetic properties and hyperfine interactions of barium hexaferrite, BaFe12−xZnxO19 (0.0≤x≤0.3) hexaferrites were synthesized via sol-gel auto-combustion technique. Rietveld analysis of XRD powder patterns confirmed the formation of single-phase hexaferrites for all products. Due to the larger ionic size of Zn2+ as compared with Fe3+, while x increases, the lattice constant parameters increase to a small degree. Nanoplate morphology of the products is presented by SEM analyses. It was observed that both saturation magnetization and coercivity decrease in almost the same manner with zinc concentration for all substitutions. Cation distribution calculations showed that Zn2+ occupies 12k, 4 f2, 4 f1, and 2b sites and at the same time pushes Fe3+ ions towards 2a and 12 k1 sites. From57Fe Mossbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting, and hyperfine magnetic field values on Zn2+ substitution have been determined.

Reductions of one-dimensional tori

Consider a non-split one-dimensional torus defined over a number field [Formula: see text]. For a finitely generated group [Formula: see text] of rational points and for a prime number [Formula: see text], we investigate for how many primes [Formula: see text] of [Formula: see text] the size of the reduction of [Formula: see text] modulo [Formula: see text] is coprime to [Formula: see text]. We provide closed formulas for the corresponding Dirichlet density in terms of finitely many computable parameters. To achieve this, we determine in general which torsion fields and Kummer extensions contain the splitting field.

Period and index, symbol lengths, and generic splittings in Galois cohomology

We use constructions of versal cohomology classes based on a new notion of "presentable functors," to describe a relationship between the problems of bounding symbol length in cohomology and of finding the minimal degree of a splitting field. The constructions involved are then also used to describe generic splitting varieties for degree 2 cohomology with coefficients in a commutative algebraic group of multiplicative type.

Microwave, dielectric and magnetic properties of Mg-Ti substituted Ni-Zn ferrite nanoparticles

Mg-Ti substituted Ni-Zn spinel ferrites (Ni0.5Zn0.5MgxTixFe2−2xO4, where 0.05≤x≤0.25) have been prepared by conventional solid state reaction method. 1wt% B2O3 was added to increase the crystal growth at low temperatures. The structural characterization of samples was performed by X-ray powder diffractometry, scanning electron microscopy and Mössbauer spectroscopy. Magnetic parameters of samples were measured by vibrating sample magnetometer at room temperature. Microwave characteristics were determined by near field measurements using a network analyzer in reflection/transmission mode. Mössbauer spectra of all the samples consist of 3 sextets and one doublet. Variation of the line width, isomer shift, quadrupole splitting and hyperfine magnetic field values have been obtained from the 57Fe Mössbauer spectroscopy data for Ni-Zn spinels having different Mg2+ and Ti4+ concentrations. The saturation magnetization of the samples decreases as the concentration of Mg-Ti ions increases, which can be explained by site preferences of the substituted cations. The electrical properties of Mg-Ti substituted Ni-Zn spinel ferrites were examined extensively as a function of temperature, frequency and Mg-Ti amount. It was found that Mg-Ti substitution has a strong effect on the ac conductivity, dielectric constant and dielectric loss mechanisms. The activation energy levels can be regulated by varying Mg-Ti concentration. There is one reflection minimum observed in the microwave characterization of the samples in the 2–18GHz range located around 10GHz in X-band, the mechanism of which is the quarter wave cancellation due to the matching thickness. The Ni0.5Zn0.5Mg0.2Ti0.2Fe1.6O4 sample has the best microwave properties with the reflection loss of −29dB at 10.4GHz for a thickness of 3mm and better than −35dB at 16GHz when thickness is decreased to 2mm. As a result, it was concluded that this material can be used as microwave absorber both in X and Ku-bands.

Synthesis and characterization of oleylamine capped MnxFe1-xFe2O4 nanocomposite: Magneto-optical properties, cation distribution and hyperfine interactions

Pure Fe3O4 NPs and Oleylamin (OAm) capped MnxFe1-xFe2O4 (MnxFe1-xFe2O4@OAm) (0.2 ≤ x ≤ 1.0) nanocomposites (NCs) were synthesized by the polyol route. Lattice parameter increases with increasing Mn2+ concentration, due to the respective larger ionic radius of Mn2+ ion compared with the Fe2+ ion. The VSM analyses revealed superparamagnetic characteristics of all samples. The extrapolated specific saturation magnetization (σs) values decreased from maximum 50.74 emu/g to minimum 15.34 emu/g by increasing Mn content. The particle size dependent Langevin function was applied to determine the magnetic particle dimensions (Dmag) between 9.10 nm and 21.50 nm. The observed magnetic moments of NPs and NCs are in range of (0.64–2.10) μB and significantly less than 4 μB of bulk Fe3O4. Magnetic anisotropy was determined as uniaxial and calculated effective anisotropy constants (Keff) are between 32.14 × 104 Erg/g and 8.71 × 104 Erg/g. The size dependent saturation magnetization suggests the existence of a magnetically dead layers around the magnetic cores for NCs between 0.72 nm and 1.29 nm. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values on Mn2+ substitution have been determined. Although, the Mössbauer spectra for the sample x = 0.2 is composed of ferromagnetic sextets, paramagnetic doublet is also formed for other samples. The percent diffuse reflectance spectroscopy (DR %) and Kubelka-Munk theory were used to specify the optical properties. The estimated optical band gap (Eg) values from Tauc plots are between 1.50 eV and 2.05 eV. Increasing Mn content in NCs increased the band gap at different magnitudes.

Effect of bimetallic (Ni and Co) substitution on magnetic properties of MnFe2O4 nanoparticles

Nickel and cobalt substituted manganese ferrite nanoparticles (NPs) with the chemical composition NixCoxMn1–2xFe2O4 (0.0≤x≤0.5) NPs were synthesized by one-pot microwave combustion route. The effect of co-substitution (Ni, Co) on structural, morphological and magnetic properties of MnFe2O4 NPs was investigated using XRD, FT-IR, SEM, VSM and Mössbauer spectroscopic techniques. The cation distribution of all products were also calculated. Both XRD and FT-IR analyses confirmed the synthesis of single phase spinel cubic product for all the substitutions. Lattice constant decreases with the increase in concentration of both Co and Ni in the products. From 57Fe Mössbauer spectroscopy data, the variations in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values with Mn2+, Ni2+ and Co2+ substitution have been determined. While the Mössbauer spectra collected at room temperature for the all samples are composed of magnetic sextets, the superparamagnetic doublet is also formed for MnFe2O4 and Ni0.2Co0.2Mn0.6Fe2O4 NPs. The magnetization and Mössbauer measurements verify that MnFe2O4 and Ni0.2Co0.2Mn0.6Fe2O4 NPs have superparamagnetic character. The saturation and remanence magnetizations, magnetic moment and coercive field were determined for all the samples. Room temperature VSM measurements reveals saturation magnetization value close to the bulk one. It has been observed that the saturation magnetization and coercive field increase with respect to the Ni and Co concentrations.

Sr1-xLaxFe12O19 (0.0≤x≤0.5) hexaferrites: Synthesis, characterizations, hyperfine interactions and magneto-optical properties

A simple sol-gel auto combustion process was used to synthesize La3+ substituted M-type strontium hexaferrite, Sr1-xLaxFe12-xO19 (0.0≤x≤ 0.5). Structural, magnetic, and optical behavior as a function of La3+ substitutions were investigated by Fourier transformed infrared spectroscopy (FT-IR). X-ray powder diffraction (XRD). Scanning electron microscopy (SEM), Mössbauer spectroscopy, vibrating sample magnetometer (VSM), and Diffuse reflectance spectroscopy (DRS). XRD data showed single phase magnetoplumbite structure and Rietveld analysis confirmed P63/mmc space group for all the series. The average crystallite size was found to be in the range of 43.2–48.4nm. The variation in line width, isomer shift, quadrupole splitting, relative area and hyperfine magnetic field values have been determined from 57Fe Mössbauer spectroscopy data. The fittings accounted for the Fe2+/Fe3+ charge compensation mechanism at the 2a site due to replacement of Sr2+ by La3+. The saturation magnetization (σs) decreases from 57,21 to 63,23emu/g and remnant magnetization (σr) decreases from 35.6emu/g to 28.7emu/g with increasing La substitution. The decrement is sharper at coercive field (Hc) from maximum value of 5325 to minimum 1825Oe. Demagnetizing factor (N) is 3 times more for the x=0.3, 0.4, and 0.5. However all samples exhibit ferromagnetic behavior at room temperature. Magnetic anisotropy of Hexaferrites was detected as uniaxial and effective anisotropy constants (Keff) were between 5.93×105 and 4.76×105 Ergs/g. The high magnitudes of anisotropy fields (Ha) in the range of 13863–15574Oe reveal that all hexaferrites are magnetic hard materials. Tauc plots were applied to extrapolate the direct optical energy band gap (Eg) of hexaferrites. The Eg values decreased from 1.83 to 1.34eV with increasing La content.

Synthesis and magneto-electrical properties of MFe2O4 (Co, Zn) nanoparticles by oleylamine route

In this study, nearly monodisperse cobalt ferrite (CoFe2O4) and zinc ferrite (ZnFe2O4) nanoparticles (NPs) without any size-selection process have been fabricated through an alluring method in an oleylamine (OAM)/benzyl ether system. Samples were synthesized by thermal decomposition of metal acetylacetonates in a high-boiling solvent and in the presence of oleylamine as surfactant and reducing agent. XRD analysis confirmed the purity and nanosized of both products and TEM analysis showed the monodispersion of them also. The oleylamine coated nanoparticles exhibited semiconducting nature at lower frequencies i.e. conductivity enhances with temperature. The dc conductivity curves of ZnFe2O4@OAm and CoFe2O4@OAm NPs indicate significant temperature-dependent behavior. The temperature and frequency-dependent variations of dielectric loss (ε″) of MFe2O4@OAm NPs display an almost sharp exponential decrease with frequency which becomes more considerable at higher temperatures and at low at low frequency regime. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values have been determined. Although the Mössbauer spectra for the ZnFe2O4@OAm consists only one paramagnetic central doublet and CoFe2O4@OAm NPs have also one paramagnetic doublet and three magnetic Zeeman sextet.

Beating patterns in the Shubnikov-de Haas oscillations originated from spin splitting in In0.52Al0.48As/In0.65Ga0.35As heterostructures: Experiment and calculation

Shubnikov-de Haas (SdH) oscillation measurements at 1.5K were carried out for In0.52Al0.48As/In0.65Ga0.35As heterostructures with different Si delta-doping concentration and spacer thickness. The dominant zero-magnetic field spin splitting mechanism is attributed to the contribution by the Rashba term due to the structure inversion asymmetry (SIA) in the In0.65Ga0.35As quantum well. The origin of the beating pattern in the SdH oscillations is investigated through the calculation of the transverse magnetoresistance versus magnetic field B by considering the Zeeman splitting and zero-magnetic field spin splitting in Si delta-doped In0.65Ga0.35As quantum wells. The good agreement between the theoretical and experimental curves suggest that the origin of beating patterns of the SdH oscillations is due to interplay of Rashba spin splitting, Zeeman splitting and Landau splitting.

Structural, magneto-optical properties and cation distribution of SrBixLaxYxFe12−3xO19 (0.0 ≤ x ≤ 0.33) hexaferrites

SrBixLaxYxFe12−3xO19 (0.0≤x≤0.33) hexaferrites were produced via sol-gel auto combustion. XRD patterns show that all the samples are single-phase M-type strontium hexaferrite (SrM). The magnetic hysteresis (σ-H) loops revealed the ferromagnetic nature of nanoparticles (NPs). The coercive field decreases from 4740Oe to 2720Oe with increasing ion content. In particular, SrBixLaxYxFe12−3xO19 NPs with x=0.0, 0.1, 0.2 have suitable magnetic characteristics (σs=62.03–64.72emu/g and Hc=3105–4740Oe) for magnetic recording. The intrinsic coercivity (Hci) above 15000Oe reveals that all samples are magnetically hard materials. Tauc plots were used to specify the direct optical energy band gap (Eg) of NPs. The Eg values are between 1.76eV and 1.85eV. 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting, relative area and hyperfine magnetic field values on Bi3+ La3+ and Y3+ substitutions have been determined.

On the splitting fields of generic elements in Zariski dense subgroups

Let G be a connected, absolutely almost simple, algebraic group defined over a finitely generated, infinite field K, and let Γ be a Zariski dense subgroup of G(K). We show, apart from some few exceptions, that the commensurability class of the field F given by the compositum of the splitting fields of characteristic polynomials of generic elements of Γ determines the group G up to isogeny over the algebraic closure of K.

Hyperfine interaction and tuning of magnetic anisotropy of Cu doped CoFe2O4 ferrite nanoparticles

Ferrimagnetic oxides may contain single or multi domain particles which get converted into superparamagnetic state near a critical size. To explore the existence of these particles, we have made Mössbauer and magnetic studies of Cu2+ substitution effect in CoFe2−xO4 Ferrites (0.0, 0.1, 0.2, 0.3, 0.4, and 0.5). All the samples have a cubic spinel structure with lattice parameters increasing linearly with increase in Cu content. The hysteresis loops yield a saturation magnetization, coercive field, and remanent magnetization that vary significantly with Cu content. The magnetic hysteresis curves shows a reduction in saturation magnetization and an increase in coercitivity with Cu2+ ion substitution. The anisotropy constant, K1, is found strongly dependent on the composition of Cu2+ ions. The variation of saturation magnetization with increasing Cu2+ ion content has been explained in the light of Neel's molecular field theory. Mössbauer spectra at room temperature shows two ferrimagnetically relaxed Zeeman sextets. The dependence of Mössbauer parameters such as isomer shift, quadrupole splitting, line width and hyperfine magnetic field on Cu2+ ion concentration have been discussed.

Dielectric properties, cationic distribution calculation and hyperfine interactions of La3+ and Bi3+ doped strontium hexaferrites

La3+ and Bi3+ doped M-type strontium hexaferrites (SrM) were prepared by sol–gel-auto combustion. X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Vibrating Simple Magnetometer (VSM), Mössbauer Spectroscopy and Novo electrical conductivity system were used for structural, morphological, and electrical characterizations of the products. The cation distribution calculations of the products were also provided. Single-phase M-type SrM with a chemical composition SrFe12−2xLaxBixO19 (0.0≤x≤0.5) were confirmed by XRD analysis, which also provided lattice constants and crystallite sizes of each product. The crystallite size was in the range of 43–51nm. SEM analysis confirmed the presence of hexagonal crystal formation while the EDX analysis confirmed the presence of metal ions in the required stoichiometric ratio. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values on Bi and La substitutions have been determined. It was observed that ac conductivity of SrM increases slightly with increasing La3+ and Bi3+ ion substitutions at first, and then fluctuates with further substitution. Moreover, ac conductivity also increased with increasing frequency which could be regarded as an indication of ionic conductivity. It can be noted that activation energy increases as the enhanced contributions of doped-ion substitutions in SrM NPs with the illustration of a better stability of electrical bonds among the substitutional ions and Fe ions.

Structural, morphological, optical, cation distribution and Mössbauer analysis of Bi3+ substituted strontium hexaferrite

Single-phase M-type hexagonal ferrites, SrBixFe12−xO19 (0.0≤x≤1.0), were prepared by a co-precipitation assisted ceramic route. The influence of the Bi3+ substitution on the crystallization of ferrite phase has been examined using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and Mössbauer spectroscopy. The XRD data show that the nanoparticles crystallize in the single hexagonal magnetoplumbite phase with the crystallite size varying between 65 and 82nm. A systematic change in the lattice constants, a=b and c, was observed because of the ionic radius of Bi3+ (1.17Å) being larger than that of Fe3+ ion (0.64Å). SEM analysis indicated the hexagonal shape morphology of products. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values on Bi substitutions have been determined.

Investigations of mechanical, electronic, and magnetic properties of non-magnetic MgTe and ferro-magnetic Mg0.75TM0.25Te (TM = Fe, Co, Ni): An ab-initio calculation

The mechanical, electronic and magnetic properties of non-magnetic MgTe and ferro-magnetic (FM) Mg0.75TM0.25Te (TM = Fe, Co, Ni) in the zinc-blende phase are studied by ab-initio calculations for the first time. We use the generalized gradient approximation functional for computing the structural stability, and mechanical properties, while the modified Becke and Johnson local (spin) density approximation (mBJLDA) is utilized for determining the electronic and magnetic properties. By comparing the energies of non-magnetic and FM calculations, we find that the compounds are stable in the FM phase, which is confirmed by their structural stabilities in terms of enthalpy of formation. Detailed descriptions of elastic properties of Mg0.75TM0.25Te alloys in the FM phase are also presented. For electronic properties, the spin-polarized electronic band structures and density of states are computed, showing that these compounds are direct bandgap materials with strong hybridizations of TM 3d states and Te p states. Further, the ferromagnetism is discussed in terms of the Zener free electron model, RKKY model and double exchange model. The charge density contours in the (110) plane are calculated to study bonding properties. The spin exchange splitting and crystal field splitting energies are also calculated. The distribution of electron spin density is employed in computing the magnetic moments appearing at the magnetic sites (Fe, Co, Ni), as well as at the non-magnetic sites (Mg, Te). It is found that the p–d hybridization causes not only magnetic moments on the magnetic sites but also induces negligibly small magnetic moments at the non-magnetic sites.

Synthesis and characterization of monodisperse NiFe2O4 nanoparticles

Narrow size distribution nickel ferrite nanoparticles with average particle size of around 6nm has been synthesized via rapid thermo-decomposition method in the presence of oleylamine in solution which acted as neutralizing, stabilizing and reducing agent OAm coated NiFe2O4 NPs. X-ray powder diffraction (XRD), Fourier Transform Infrared Spectra (FT-IR), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), Vibrating Simple Magnetometer (VSM) and also Mössbauer Spectroscopy were used for structural, morphological, spectroscopic and magnetic characterization of the product. The XRD analysis revealed the formation of single phase nickel ferrite with Fd-3m space group. Both FT-IR and TGA analyses confirmed the formation of desired nanocomposite. FT-IR analysis also showed characteristic IR absorption bands of the spinel nickel ferrite phase and oleylamine. TEM and SEM analysis showed that product have almost spherical structural morphology. TEM images showed that NiFe2O4 nanoparticles have narrow size distribution and Energy Dispersive X-ray (EDX) analysis confirmed the presence of metal ions in the required stoichiometric ratio. Superparamagnetic property of the product was confirmed by VSM. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values have been determined. The Mössbauer spectra for OAm coated NiFe2O4 NPs. is consisting of one paramagnetic central doublets and one magnetic Zeeman sextet. Finally, the synthetic procedure can be extended to the preparation of high quality metal or alloy nanoparticles.

Magneto-optical investigation and hyperfine interactions of copper substituted Fe3O4 nanoparticles

Copper substituted Fe3O4 nanoparticles (NPs) (CuxFe1−xFe2O4 (0.0≤x≤1.0)) were synthesized by polyol method and the effect of Cu2+ substitution on structural, magnetic and optical properties of Fe3O4 was investigated. X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), UV–Visible spectroscopy and Vibrating sample magnetometer (VSM) were used to study the physical properties of the products. The room temperature (RT) magnetization (σ–H) curves revealed the superparamagnetic nature of the products. The extrapolated specific saturation magnetization (σs) decreases from 42.69emu/g to 14.14emu/g with increasing Cu content (x). The particle size dependent Langevin fit studies were applied to determine the magnetic particle dimensions (Dmag). The average magnetic particle diameter is about 9.89nm. The observed magnetic moments of NPs are in range of (0.61–1.77) µB and rather less than 4µB of bulk Fe3O4 and 1µB of bulk CuFe2O4. Magnetic anisotropy was assigned as uniaxial and calculated effective anisotropy constants (Keff) are between 10.89×104Erg/g and 26.95×104Erg/g. The average value of magnetically inactive layer for CuxFe1−xFe2O4 NPs was calculated as 1.23nm. The percent diffuse reflectance spectroscopy (DR%) and Kubelka–Munk theory were applied to determine the energy band gap (Eg) of NPs. The extrapolated optical Eg values from Tauc plots are between minimum 1.98eV to 2.31eV. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer splitting, quadrupole splitting and hyperfine magnetic field values on Cu+2 ion substitution have been determined. Although, the Mössbauer spectra for the sample x=0.2 and 0.8 are composed of paramagnetic doublets, ferromagnetic sextets were also formed for other products.

Interactions between charged surfaces mediated by stiff, multivalent zwitterionic polymers.

The interaction between like-charged objects in electrolyte solutions can be heavily altered by the presence of multivalent ions which possess a spatially distributed charge. In this work, we examine the influence of stiff, multivalent zwitterionic polymers on the interaction between charged surfaces using a splitting field theory previously shown to be accurate for the weak to the intermediate to the strong electrostatic coupling regimes. The theory is compared to Monte Carlo simulations and good agreement is found between both approaches. For surface separations shorter than the polymer length, the polymers are mainly oriented parallel to the surfaces, and the surface-surface interaction is repulsive. When the surface separation is comparable to the length of polymers, the polymers have two main orientations. The first corresponds to the polymers adsorbed onto the surface with their centers located near to or in contact with the surface; the second corresponds to polymers which are perpendicular to the charged surfaces, bridging both surfaces and leading to an attractive force between them. Increasing the surface charge density leads to more pronounced attraction via bridging. At surface separations greater than the polymer length, the polymers in the center of the system are still mainly perpendicular to the surfaces, due to "chaining" between zwitterions that enable them to bridge the surfaces at larger separations. This leads to an attractive interaction between the surfaces with a range significantly longer than the length of the polymers.

Structural investigation and hyperfine interactions of BaBixLaxFe12−2xO19 (0.0≤x≤0.5) hexaferrites

Barium hexaferrite, BaFe12O19, substituted by Bi3+ and La3+ (BaBixLaxFe12−2xO19 where 0.0≤x≤0.5) were prepared by solid state synthesis route. The effect of substituted Bi3+ and La3+ ions on the structure, morphology, magnetic and cation distributions of barium hexaferrite were investigated by X-ray powder diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR) and Mössbauer spectroscopy. XRD powder patterns were refined by the Rietveld analysis method which confirmed the formation of single phase magneto-plumbite structure and the substitution of La3+ and Bi3+ ions into the lattice of barium ferrite. These results show that both La3+ and Bi3+ ions completely enter into barium hexaferrite lattice without disturbing the hexagonal ferrite structure. The EDX spectra confirmed the presence of all the constituents in expected elemental percentage. From 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting and hyperfine magnetic field values on Bi and La substitutions have been determined. Cation distribution in the presently investigated hexaferrite system was estimated using the relative area of Mössbauer spectroscopy.