MH Loops Research Articles

Cationic migration effect on the dielectric and magnetic properties of CoFe2O4/ZnO composites

The present paper focusses on the effect of cationic migration in the sintered CoFe2O4/ZnO composite. The increase in lattice parameter of the CoFe2O4 after sintering indicates substitution of Zn. Mӧssbauer analysis of the samples indicates the transformation of composites to paramagnet in the sample sintered at 600 and 750 °C. At 900 °C, a low hyperfine field sextet was evolved complimented by MH loop which is due to redistribution of cations and formation of ferromagnetic phase. Maxwell-Wagner dispersion was identified by the frequency-dependent fluctuation of dielectric constants (ε׳) and dielectric loss (tan δ). Dielectric constant values of 8.66, 7.90, 9.31 and dielectric loss value of 0.11, 0.03, 0.05 were found for CZ6, CZ7 and CZ9 respectively at 1 MHz frequencies. The composite are suitable for high frequency applications due to its low loss, high resistance, low sintering temperature. The mechanisms behind these observations are discussed in this paper.

Influence of Cu2+ substitution on the structural, optical, magnetic, and antibacterial behaviour of zinc ferrite nanoparticles

Ferrite nanoparticles are an emerging material for industrial and biomedical applications. Herein, a simple non-aqueous sol–gel method is used to synthesize CuxZn(1-x)Fe2O4 (x = 0.0, 0.25, 0.5, and 0.75) nanoparticles. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectroscopy, and a vibrating-sample magnetometer (VSM) were utilized to investigate the structural formation and magnetic merits of the prepared ferrite nanoparticles. The Rietveld refinement of the X-ray diffraction pattern confirmed the formation of single-phase cubic structures with Fd3¯m space groups for all samples. The increase in cu2+ concentration in zinc ferrite nanoparticles decreases the lattice parameters from 8.4418 to 8.4368. The energy gap of cu2+-doped zinc ferrite increases from 1.89 to 2.04 eV with a decrease in particle size. MH loop revealed an increase in Ms and Mr Parameters as Hc reduces with an increase in Cu2+ concentration in the zinc ferrite matrix. It was discovered that an increase in Cu2+ content improved the antibacterial activities of Cu2+-doped zinc ferrite against all bacterial species.

Enhanced multiferroicity of Ho0.95Co0.05Fe0.95Ti0.05O3 by co-doping in HoFeO3 nanoparticle system

Nanocrystalline HoFeO3 is a potential multiferroic and will be more useful if its multiferroicity can be enhanced by improving the magnetic and electric ordering. In this regard, co-doping with Co and Ti, was considered in HoFeO3 (HFO) to enhance its magneto-electric behavior and thus synthesize a new monophasic multiferroic, Ho0.95Co0.05Fe0.95Ti0.05O3 (HCFTO). Both the pristine and doped HFO nanoparticles were synthesized in sol–gel route. Rietveld analyses of X-ray diffractograms, confirmed the formation of pure orthorhombic (Pnma) phase of both bare and doped HFO. Presence of the canted antiferromagnetism of bare HFO at room-temperature with antiferromagnetic transition at ∼ 637 K was confirmed in susceptibility vs. temperature variation and by the nature of MH loops. Interestingly, substantial enhancement of magnetism was observed in HCFTO compared to that of bare one, where the room-temperature maximum magnetization is enhanced by 73%. Dielectric strength of HFO (∼48) is also enhanced highly (∼3.4 times) in HCFTO (∼165), and the loss factor is lowered to nearly half. Current density vs. electric field (J-E) curve suggests the presence of polarization at room temperature with negligible leakage loss. Lower leakage loss of HCFTO indicates better multiferroicity than HFO. Direct measurement of ferroelectric loop shows the room-temperature ferroelectricity of bare HFO (Pmax ∼ 0.0041 µc/cm2) well improved (∼1.5 times) in the doped HCFTO (Pmax ∼ 0.0061 µc/cm2) with lower hysteresis loss. Room-temperature magnetoelectric coupling measurements, shows a high value (∼2.47%) of magnetocapacitance in the doped system, which is much higher (∼4.94 times) than the bare one (∼0.5%). All these properties of the sample clearly confirm the co-doping in the HoFeO3 nanoparticle system results in a considerable improvement in its magnetoelectric behavior, and this co-doped Ho0.95Co0.05Fe0.95Ti0.05O3 system can be a promising and potential magnetoelectric multiferroic for device applications.

Multiferroic properties and magnetoelectric coupling observed in nanocrystalline HoFeO3

Nanocrystalline holmium orthoferrite (HoFeO3) was synthesized by the chemical sol-gel technique. The main focus of attention was to explore the behavior of nanocrystalline system of HoFeO3 in the context of multiferroicity. Structural investigation by observing X-ray diffractograms and its thorough Rietveld analysis was carried out in detail which confirms the deviation in crystallographic structure. Structural study confirms the pure orthorhombic (Pnma) phase of HoFeO3 with zero impurity including the presence of uniform particle size distribution in the nano regime. Different useful structural parameters were also calculated from this theoretically generated pattern, which help to understand the magnetoelectric behavior explored in the sample. Surface morphology studied by FESEM micrographs confirmed a more or less uniform grain distribution in nano regime. EDAX spectra and mapping confirms the elemental purity. Thermal variation of magnetization measurements of HoFeO3 was carried out under zero-field cooled and field (~200 Oe) cooled conditions. Also, variation of magnetization with field (MH Loop) yields the presence of magnetic ordering with a relatively high value of magnetization compared to its corresponding bulk counterpart. During field-variation, magnetization value wasn’t yet saturated even at the maximum applied field of ~3 T, indicating the presence of magnetic ordering and superparamagnetism. Detailed high-temperature dielectric study including thermal variation, as well as frequency variation of dielectric constant together with related electric parameters provide various important information like ferro to para transition temperature, etc. These observations and various analyzes including Cole-Cole analysis of frequency variation of permittivity, Nyquist plot impedance analysis, etc. provide all dielectric parameters which are essential to understand the dielectric properties of the sample. The studies of ferroelectric loop and presence of room temperature magnetoelectric coupling suggest type-II multiferroicity of the present system of HoFeO3, which is usually not found in the bulk system. Presence of prominent remnant polarization with feeble dielectric loss and substantial magnetization clearly establishes the multiferroic candidature of nanocrystalline HoFeO3. This signature of multiferroicity will definitely strengthen the quality of application of the sample in M-E devices.

Lithium ferrite (Li0.5Fe2.5O4): synthesis, structural, morphological and magnetic evaluation for storage devices

Lithium ferrite Li0.5Fe2.5O4 has been synthesized by the use of the sol–gel technique. X-ray diffractometer (XRD) has been employed to confirm the crystal structure of spinel ferrites. No impurity peaks are detected in XRD graph, which confirms single phase crystal structure. The evaluation of grain size and analysis of external surface morphology of synthesized lithium ferrites has been done by scanning electron microscope (SEM). Average grain size was about equal to 131 nm. Energy dispersive x-ray spectra showed all the elements were present in required proportions. Magnetic characteristics such as saturation magnetization (Ms), remanence (Mr), and coercive force (Hc) have been measured from MH loops. Saturation magnetization has been measured to be 43.69 emu/by law of approach to saturation. The coercivity value lies in the range of few hundred Oersted which is vital condition for electromagnetic materials. Cyclic Voltammetry (CV) measurements were made, to know about the electrochemical performance of the material. CV results show that with the increase in scan rate specific capacitance decreases and the area of the loop increases which is promising for the formation of super capacitors and lithium-ion batteries (LIB's).

Comparative Study of Specific Loss Power and Transverse Relaxivity of Spinel Ferrite Nanoensembles Coated With Chitosan and Polyethylene Glycol

We synthesized spinel ferrite nanoensembles (MnFe2O4, CoFe2O4, and Fe3O4) using the chemical co-precipitation method and characterized their physical, chemical, and magnetic properties by X-ray diffraction (XRD), transmission electron microscopy (TEM), physical properties measurement system (PPMS), Mössbauer spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and Raman spectroscopy. Their relaxation properties and potential for hyperthermia therapy were determined using nuclear magnetic resonance (NMR) and cell viability assay, respectively. XRD and TEM data confirmed that the particle core sizes were 6–9 nm before coating while their sizes increased to 10–14 nm and 14–20 nm after coating with chitosan and polyethylene glycol (PEG), respectively. Mössbauer spectroscopy showed superparamagnetic behavior for MnFe2O4 nanoparticles and ferrimagnetic behavior for the CoFe2O4 and Fe3O4 nanoparticles. A detailed studies of MH loops of all three ferrites before and after coating showed surface functionalization by a large reduction of coercivity and anisotropy. The successful coating was further confirmed by the peak shifts in the FTIR spectra of the particles whereas Raman spectra of coated ferrites also displayed the characteristic absorption patterns and suppression of the ferrite peaks suggesting successful coating. The induced heating profile of the nanoparticles in stable suspension was tested with a radio frequency magnetic field of 76 mT and a frequency of 400 kHz. High mortality (>98%) of 9 L gliosarcoma cancer cells by hyperthermia suggested that these nanoparticles could be used for cancer therapy. Transverse relaxivities (r2) determined by NMR for chitosan-coated MnFe2O4, CoFe2O4, and Fe3O4 nanoparticles were 297 (±22), 353 (±26), and 345 (±13), mM−1S−1, while for PEG-coated nanoparticles are 165 (±22), 146 (±14), and 159 (±07) mM−1S−1, respectively. Overall these spinel ferrite nanoensembles show great promise for cancer theranostics research applications.

Effect of Ceramic Fillers on the Dielectric, Ferroelectric and Magnetic Properties of Polymer Nanocomposites for Flexible Electronics

Polymer nanocomposites have been investigated for their flexibility, light weight, low production cost and conformability to different shapes. In this paper, the functional properties of the polymer nanocomposites are studied by varying the ceramic fillers with bismuth ferrite, dysprosium (Dy) doped bismuth ferrite and gadolinium (Gd) doped bismuth ferrite. The developed polymer nanocomposites are seen to possess excellent magneto-dielectric behaviour, a property well-suited for developing high-frequency microwave devices. The ceramic nanoparticles were successfully synthesized using methoxy assisted sol–gel technique. The synthesized nanoparticles were subjected to crystallographic and structural characterization. The x-ray diffraction (XRD) pattern illustrated the phase purity and crystalline phases of the nanoparticles with grain sizes ranging from 60 to 90 nm. The morphology of the nanoparticles was studied through scanning electron microscopy (SEM). The nanoparticles were dispersed in the polymer matrix using solution casting to form polymer-ceramic nanocomposite films. The films were subjected to broadband dielectric characterization in the X band of the frequency spectrum and films exhibited magneto-dielectric property with values of e' and µ' greater than one. The ferroelectric and ferromagnetic behaviours of the material at room temperature were studied from the PE and MH loops. Moreover, the nanocomposite films are biodegradable within a few minutes of immersion in water and can be used for transient electronics. Findings from the research can promote the invention of more materials for flexible and transient electronic devices.

Exchange bias, and coercivity investigations in hematite nanoparticles

<abstract> <p>Hematite nanoparticles of average size of 20 nm were synthesized using sol-gel method and the structural characterisations were conducted using XRD and TEM. The XRD profile revealed the coexistence of small fraction of maghemite phase along with the main hematite phase. Magnetization versus applied field (M-H) measurements were performed between −5 and 5 T and respectively in the temperatures 2, 10, 30, 50, 70,100,150,200, and 300 K under zero field and 1, 2, 3, 4 T field cooling. At all field-cooling values, the coercivity was found to display a weak temperatures dependence below 150 K and a strong increase above 150 K reaching the largest value of 3352 Oe at 300 K for the field-cooling value of 3 T. Horizontal and vertical hysteresis loop shifts were observed at all temperatures in both the zero-field and field-cooled states. In the field-cooled state, both loop shifts where found to have significant and nonmonotonic field-cooling dependences. However, because saturation magnetization was not attained in all measurements our calculations were based on the minor hysteresis loops. M-H measurements were performed between −9 and 9 T at room temperature under zero field cooling and 1, 2, 3, 4, 5, 6 T field cooling. Saturation magnetization was not attained, and the loops displayed loop shifts similar to those for the ±5 T sweeping field. The highest coercivity value of 4400 Oe is observed for the 6 T field cooled MH loop. The ferromagnetic (FM) contribution towards the total magnetization was separated from the total magnetization and hysteresis loops displayed both horizontal and vertical shifts. The novel results of the temperature and field dependence of exchange bias were attributed mainly to the magnetic exchange coupling between the different magnetic phases (mainly the FM) and the spin-glass-like regions.</p> </abstract>

Effect of Cr3+ substitution on magnetic and electrical properties of (Ni0.3Cu0.7) Fe2O4 spinel ferrites

Chromium substituted copper base spinel ferrites (Ni0.3Cu0.7)CrxFe2-xO4 were prepared by Sol-gel method. Structural, magnetic and electrical properties were studied by utilizing X-ray diffractometer, Vibrating sample magnetometer, and precision LCR-meter using lab-tracer software. The X-ray diffraction analysis confirmed the formation of single phase fcc structure of the samples. The lattice constant and crystallite size decreased from 8.37-8.23Å and 53.09-35.36nm respectively with increasing content of Cr3+ ions. From MH loops it was observed that the saturation magnetization decreased and coercivity increased with increasing content of Cr3+ ions. Dc resistivity increased with increase of Cr3+ concentration and decreased with increase in temperature which shows the semiconducting behavior of ferrites. The dielectric constant, dielectric loss and tangent loss decreased with increase of Cr3+ concentration. The dielectric constant follows bilayer Maxwell Wagner model and Koop’s phenomenological theory while ac conductivity increased with increasing frequency following Jonscher’s power law.

Structural, morphological and cryogenic magnetic behaviour of double perovskite La1.9Sr0.1NiMnO6−δ thin film

This work presents the investigation on structural, morphological and cryogenic/temperature-dependent magnetic studies carried on the hole-doped double perovskite La1.9Sr00.1NiMnO6−δ thin film. The optimized film was deposited on Si (100) substrate through pulsed laser ablation. The film was characterized by the techniques, grazing incidence X-ray diffraction (GIXRD), atomic force microscopy (AFM), Raman and temperature-dependent magnetization. GIXRD patterns revealed the polycrystalline structure to be monoclinic and possessing P21/n space group. The tensile strain was detected in the film and estimated from the Williamson-Hall equation. AFM micrographs revealed the average grain size and the film roughness. Raman peaks corresponding to the wavenumbers 530 cm−1 and 657 cm−1, respectively represent the asymmetric and symmetric modes of the NiO6/MnO6 octahedra. Besides, magnetic studies revealed the ferromagnetic nature of the film at cryogenic temperature (5 K) as depicted by the MH loop along with the curie temperature of 186.9 K was obtained from the MT plots.

Dominance of Shape Anisotropy among Magnetostatic Interaction and Magnetocrystalline Anisotropy in Electrodeposited (FeCo)1−xCux (X = 0.1–0.5) Ternary Alloy Nanowires

The (FeCo)1−xCux (X = 0.1–0.5) nanowire (NWs) arrays were synthesized through AC-electrochemical deposition in anodized aluminum oxide (AAO) templates. The morphology and composition of the synthesized (FeCoCu) NWs were found from scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) that confirmed the diameter of the NWs is in the range of 50–60 nm and the composition of FeCoCu alloy NWs, respectively. The XRD measurement of the NWs was carried out in AAO templates along with Al-substrate. The FeCoCu alloy NWs show BCC phase along with reflection peak (311) in all samples which corresponds to Al-substrate. The crystallite size displays overall increasing trend confirmed through XRD using Scherrer equation. The magnetic analysis reveals that by increasing the Cu concentration in FeCoCu alloy NWs, the saturation magnetization and coercivity (Hc) decreased. The results of MH loops confirmed that easy axis lies along the NWs and hard axis perpendicular to the NWs due to dominance of shape anisotropy. Magnetization reversal mechanism occurs by nucleation mode with the motion of domain walls. The frequency-dependent dielectric analysis investigated thoroughly using impedance and the behavior of dielectric parameters has been examined using Maxwell-Wagner’s model and Koop’s theory. The value of dielectric constant decreases progressively with increasing frequency and vice versa. It is also observed that with increase in Cu concentration, the dielectric constant also decreases due to higher conductivity of Cu than Fe and Co.

Structural and Uniaxial Magnetic Anisotropy of Co1-XMgX(X = 0.04–0.12) Nanowires in Alumina Templates

The nanoporous anodized aluminum oxide (AAO) templates were synthesized by two-step anodization in a solution of 0.5 M phosphoric acid at 60 V and temperature T ~ 0 °C. The CoMg nanowires were synthesized by template-based AC Electrodeposition technique at different voltages by AC source 13–17 V at room temperature. These CoMg nanowires were investigated via different characterization techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). The SEM result shows that nanowires have average diameter about 150 nm and length about 23 μm. The EDX reveals that nanowires only consisted of Mg and Co atoms, and atomic ratio of Mg/(Co + Mg) showed increasing tendency with deposition voltage which depicts that higher AC electrodeposition voltage is more suitable for Mg-rich deposition. The XRD results show that CoMg nanowires have hexagonal crystal structure with polycrystalline nature. The MH loops confirm that nanowires are soft ferromagnetic with uniaxial magnetic anisotropy. It is observed from angular dependence of coercivity that magnetization reversal mechanism occurs by a combination of curling and nucleation mode. The squareness (Mr/Ms) is found to be 0.24 along nanowires and 0.16 perpendicular to nanowire axis suggesting that easy magnetization direction lies along the nanowires. The effective anisotropy is observed along the nanowire axis due to dominance of shape anisotropy and suppression of dipole-dipole interactions among nanowires.

Effect of grain size on exchange-spring mechanism of [BaFe12O19 (BaM)-Na0.5Bi0.5TiO3 (NBT)] magnetoelectric composite system

Abstract Four magnetoelectric (ME) composite systems: having composition [80 wt% BaFe12O19 (BaM) – 20 wt% Na0.5Bi0.5TiO3 (NBT)] considering the variation of grain size of both the phases are synthesized by solid state method. X-ray diffraction, FESEM and TEM studies are employed to confirm the pure phase formation, grains size and connectivity of both the phases in composite systems. The exchange-spring mechanism (ESM) has been examined with the help of MH loops and magneto transport studies. From analysis it has been found that spin polarized electron tunnelling at ferromagnetic (FM)-insulator (I) interfaces has significant effect on ESM.

Influence of diamagnetic Zn on structural, ferroelectric and ferromagnetic properties of BiFe1-xZnxO3 (0% ≤ x ≤ 8%)

Nanocrystallites with the compositional formula BiFe1-xZnxO3 (x = 0.0, 0.01, 0.03, 0.05, 0.08) were synthesised by sol-gel method route. The influence of Zn doping on structural, dielectric, ferroelectric and ferromagnetic properties was discussed in detail. XRD studies confirmed the crystallinity and phase formation of all the samples. Slight lattice distortion has been observed for x = 0.08 sample as compared to the pure phase BiFeO3 (BFO). Microstructural investigations using SEM showed the increase in grain size with the increase in Zn addition. FTIR studies reveal the presence of necessary bonds in the samples. Enhanced dielectric and ferroelectric properties have been observed with Zn doping upto x = 0.05 concentration and then decreases. Room temperature MH loop showed enhanced ferromagnetic properties upto x = 0.03 Zn content and decreases thereafter. Explanation of the above results was discussed extensively. Simultaneous improvement in both ferroelectric and ferromagnetic properties might bring considerable interest in various multiferroic applications.

Structural, electrical and magnetic properties of multiferroic NdFeO3–SrTiO3 composites

The investigation on the structural, electric and magnetic properties of (1 − x)NdFeO3–xSrTiO3 composites with x = 0.1, 0.2, 0.3 and 0.4 is presented in this work. The composites of NdFeO3(NFO) and SrTiO3(STO) have been prepared by the conventional solid-state reaction method. The composite samples have been investigated by XRD, PE loop tracer, dielectric and VSM measurements. The XRD patterns confirm the formation of the phases in the composites. The ferroelectric and ferromagnetic properties observed by PE and MH loops respectively imply their multiferroic nature. The observed value of saturation polarisation in the sample with x = 0.3 is found to be 0.7 µC/cm2 and the saturation magnetisation has the maximum the value of 3.22 emu/g for the sample with x = 0.4. The overall value of dielectric constant has also got enhanced in all the composite samples and has been found to be maximum for the sample having x = 0.4.

Spin State of Cobalt and Electrical Transport Mechanism in MgCo2O4 System

MgCo2O4 samples were synthesized by inverse co-precipitation method. The formation of a single-phase spinel structure was confirmed by X-ray diffraction measurements and Fourier-transform infrared spectroscopy. The samples crystallized in a face-centered cubic structure with Fd-3m space group as revealed from the Rietveld refinement of X-ray diffraction data. Magnetic measurements carried out in a broad temperature range of 5–300 K showed antiferromagnetic to paramagnetic phase transition (Neel temperature) observed at 101 K. Magnetic susceptibility data fitted using the Curie Weiss law and effective Bohr magnetic moment (μeff) for Co atoms was determined. Calculated μeff comes out to be 3.05 μB. These results were correlated to the spin states of Co3+ atoms. A small hysteresis in the field-dependent magnetization MH loop taken at 5 K indicates the existence of weak ferromagnetism in this system. The electrical resistivity measurement in the temperature range 77–750 K displayed the semiconducting-like behavior for this system.

Structural elucidation, and morphological and magnetic behavior evaluations, of low-temperature sintered, Ce-doped, nanostructured garnet ferrites

Low-temperature sintered CexGd3.5-xFe4.5O12 (x = 0.0, 0.4, 0.8, 1.2, 1.6, 2.0 and 2.4) garnet ferrites were synthesized via a sol-gel self-combustion route. Phase, structure, morphology and magnetic investigations were done using FTIR, XRD, FESEM, and VSM, respectively. Single-phase structures of all Ce3+ substituted nano-sized garnet ferrites were confirmed through XRD. The crystallite size was decreased with Ce3+incorporation. Relevant structural parameters such as site radii, bond lengths, ionic radii, and shared edges were calculated using XRD. The vibrational spectroscopy stretching band studies were also done using FTIR. The grain size and morphology were also analyzed using FESEM. The magnetic remanance, saturation, and coercivity were found to increase systematically with an increase in Ce3+ concentration in these garnets. Switching field distribution curves were also plotted using the first derivative of the demagnetization data from MH loops. The better magnetic properties of these nanogarnets suggest their use for miniaturization of the devices in various applications.

Structural, electrical and magnetic properties of multiferroic BiFeO3–SrTiO3 composites

We have investigated the structural, electric and magnetic properties of composites of antiferromagnetic–ferroelectric BiFeO3 (BFO) and quantum para-electric SrTiO3 (STO) perovskite oxides. The composites (1−x)BFO-xSTO, with x = 0.1, 0.2, 0.3 and 0.4 have been prepared employing the conventional solid state reaction method. The samples were characterised by XRD, Fourier transform infrared spectroscopy (FTIR), PE loop tracer, JE, VSM, dielectric measurements. The XRD patterns confirm the phase formation and has led to calculate the structural parameters. The FTIR spectra have been used for determining the Fe–O bond length. The PE and MH loops enable us to determine electric and magnetic hysteresis respectively. The x = 0.2 samples shows the finest ferromagnetism and the x = 0.4 sample shows the optimal ferroelectricity at room temperature. These composites show ferroelectric and ferromagnetic properties at room temperate, implying the multiferroic nature.

Influence of barrier thickness on Ni50.3Mn36.9Sb12.8/BiFeO3/Ni50.3Mn36.9Sb12.8 multiferroic tunnel junctions

Abstract Effect of antiferromagnetic barrier layer (BiFeO 3 ) thickness on tunneling properties in Ni 50.3 Mn 36.9 Sb 12.8 /BiFeO 3 /Ni 50.3 Mn 36.9 Sb 12.8 multiferroic tunnel junction fabricated on Si substrates had been thoroughly investigated. The exchange bias phenomenon is also found to be present with the thickness of barrier layer larger than 10 nm, exhibiting prominent shift in MH loop of Ni 50.3 Mn 36.9 Sb 12.8 /BiFeO 3 /Ni 50.3 Mn 36.9 Sb 12.8 trilayer. The value of TEMR ratio increases with increase in barrier layer thickness for thickness below 10 nm and decreases above it. These finding may be helpful towards novel reconfigurable logic spintronics architectures in next generation electrically controlled random access memory devices.

Multiferroism of [Na0.5Bi0.5TiO3 – BaFe12O19] lead-free novel composite systems

Polycrystalline (1-x) Na0.5Bi0.5TiO3 – (x) BaFe12O19 [x in wt%=10, 20, 30 and 40] novel magnetoelectric composites are synthesized by solid state reaction method. The formation of composites is confirmed by Rietveld refinements of XRD patterns. The connectivity of both phases and grain size are verified from SEM images. Room temperature (RT) multiferroism has been verified by PE loop, MH loop, magnetocapacitance (MC%) and magnetoloss (ML%) studies. From results it is found that, Ps and Pr increases with BaM wt% up to certain wt% and then decreases, however, Ms increases & Hc decreases continuously. Highest MC% and ML% are observed in S1(NBT90). From analysis it is perceived that, connectivity of BaM-BaM & BaM-NBT interfaces have significant role on multiferroic behaviour.