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Exploring the electromagnetic shielding behavior of lanthanum doped calcium nanoferrites

Journal of Rare Earths 2024年第11期42卷 2128-2136,I0005页

作者： E.Ahilandeswari K.Sakthipandi R.Rajesh Kanna G.Rajkumar B.Ganesh Babu S.Arunmetha Aslam Hossain P.Sakthivel V.Rajendran M.Srinidhi Raghavan Department of Physics SRM TRP Engineering CollegeTiruchirappalli621105Tamil NaduIndia Department of Electronics and Communication Engineering M.Kumarasamy College of EngineeringKarur639113Tamil NaduIndia Department of Physics Easwari Engineering CollegeChennai600089Tamil NaduIndia Department of Mechanical Engineering SRM TRP Engineering CollegeTiruchirappalli621105Tamil NaduIndia Centre for Advanced Energy Studies Department of Electronics and Communication EngineeringKoneru Lakshmaiah Education FoundationGunturAndhra Pradesh522502India Smart Materials Research Institute Southern Federal UniversitySladkova 178/24344090Rostov-on-DonRussia Centre for Materials Science Department of PhysicsScience and HumanitiesFaculty of EngineeringKarpagam Academy of Higher EducationCoimbatore641021Tamil NaduIndia Centre for Nanotechnology Academy of Maritime Education and Training(Deemed to be University)Chennai603112Tamil NaduIndia Department of Chemistry and Centre for Nano-Materials and Displays B.M.S.College of EngineeringBengaluru560019KarnatakaIndia

The present study focuses on the synthesis and characterization of lanthanum(La^(3+))-doped calcium nanoferrites(CaLa_(x)Fe_(2-x)O_(4):x=0.025,0.050,0.075 and 0.100)using the sonochemical *** techniques were employed to analyze the effect of La^(3+)infusion,Raman spectroscopy confirms the presence of active A_(1g),T_(2g)and E_g modes in the CaLa_(x)Fe_(2-x)O_(4)nanoferrite,indicating the formation of an active ferrite *** introduction of La^(3+)doping results in a significant increase in the band gap energy,rendering the nanoferrites insulating(3.23-3,57 eV).At higher frequencies,the impedance studies reveal minimal losses and better AC conductivity,pointing to improved dielectric *** higher frequencies,the Q-factor of La-doped calcium nanoferrites shows lower electromagnetic *** M-H curve exhibits ferromagnetic behavior,with La^(3+)-doped calcium nano ferrites displaying a saturation magnetization ranging from 12.72 to 18.10 emu/*** incorporation of La^(3+)also induces enhanced electrical polarization,leading to notable dielectric loss and increased absorption of electromagnetic ***,these CaLa_(x)Fe_(2-x)O_(4)nanoferrites demonstrate potential as effective microwave absorbers across a wide frequency range,with significant shielding absorption observed at 8.8-9.1 GHz.

关键词： nanoferrites Structural properties Rare earths Dielectric Magnetism Microwave absorption

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Y^(3+) substituting-adjusted mechanical,dielectric,and impedance properties of cobalt copper zinc nanoferrites for high frequency applications

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Journal of Rare Earths 2023年第10期41卷 1597-1605,I0005页

作者： S.F.Mansour N.S.Al-Bassami M.Afifi M.A.Abdo Physics Department Faculty of ScienceZagazig UniversityZagazigEgypt General Studies Department Jubail Industrial CollegeJubail Industrial CitySaudi Arabia Faculty of Nanotechnology for Postgraduate Studies Cairo UniversityEl-Sheikh Zayed12588Egypt

Upgrading mechanical-dielectric features of ferrites through rare-earth yttrium(Y^(3+))doping provides feasibility to evolving high-frequency electronic *** paper reports the mechanical and dielectric properties of Co_(0.5)Cu_(0.25)Zn_(0.25)Y_(x)Fe_(2-x)O_(4)ferrite nanoparticles labeled as CCZYF#0,CCZYF#1,CCZYF#2,CCZYF#3,CCZYF#4 and CCZYF#5 for x=0.***.0.02,0.04,0.06,0.08,and 0.1,*** frequency and temperature dependence of dielectric parameters and co nductivity of all CCZYF nanoferrites are well *** nanoferrite CCZYF#5 has the highest dielectric constant(enhancing ratio 170%)and the highest conductivity(enhancing ratio 7125.81%)compared with the undoped *** plots of all CCZYF nano ferrites manifest two arcs;the main reasons for the dielectric process are the grain boundaries and bulk *** impedance parameters were determined,which showed the effective role of Y^(3+)ions on their *** nanoferrite CCZYF#5 has the highest grain boundaries capacitance(with enhancing ratio of 59.40%)and the highest grains capacitance(with enhancing ratio of 22.53%)with a relaxation time decrement efficiency of 62.51%.An ultrasonic flaw detector was utilized to determine the elastic moduli of all CCZYF *** nanoferrite CCZYF#5 has the highest longitudinal modulus(with enhancing ratio of 20.95%),the highest shear modulus(with enhancing ratio of48.72%),highest Young's modulus(with enhancing ratio of 88.47%),the highest bulk modulus(with enhancing ratio 13.27%)and the highest micro hardness(with enhancing ratio 77.77%).Hence,Y3+tuned Co-Cu-Zn nanoferrites possess new opportunities for high-frequency and storage applications.

关键词： nanoferrites Rare arth ions Mechanical properties Dielectric parameters Impedance spectroscopy

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Doping effect of rare-earth(lanthanum, neodymium and gadolinium) ions on structural,optical, dielectric and magnetic properties of copper nanoferrites

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Journal of Rare Earths 2018年第12期36卷 1299-1309页

作者： R. Rajesh Kanna K. Sakthipandi S.M.Seeni Mohamed Aliar Maraikkayar N. Lenin M. Sivabharathy Department of Physics Sethu Institute of Technology Department of Computer Science and Engineering Sethu Institute of Technology

Copper and rare earth-doped(RE = La, Gd, Nd) CuFe1.85RE0.15O4nano ferrites were prepared using the so nochemical method. The effective doping of rare-earth(La3+, Nd3+, Gd3+) ions with copper nanoferrites was confirmed by X-ray diffraction. The tetrahedral and octahedral sites of the nano ferrites were identified through the Fourier transform infrared spectra. The doping of rare-earth elements enhances the optical bandgap energy of the nanoferrites that are observed through Ultraviolet-DRS spectra. The oxidation state of the elements Cu 2 p, La 3 d, Nd 3 d, Gd 3 d, Fe 2 p and O 1 s was analyzed. Scanning electron microscopy images indicate a spherical morphology with agglomeration to some elongate. The values of dielectric constant and conductivity decrease considerably due to doping rare-earth ions in copper nanoferrites. Low saturation magnetization and high coercivity values of rare earth-doped copper nanoferrites are observed from the typical hysteresis curves.

关键词： nanoferrites Optical properties Dielectric response Magnetic measurements Rare earths

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Unique structural and magnetic traits of Nd3+-substituted Co-Zn nanoferrites

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Journal of Rare Earths 2019年第10期37卷 1108-1115页

作者： M.A.Almessiere Department of Physics College of Science Imam Abdulrahman Bin Faisal University Department of Nano-Medicine Research Institute for Research & Medical Consultations (IRMC) Imam Abdulrahman Bin Faisal University

Because of the technological potential of magnetic spinel nanoferrites, we prepared neodymium ion(Nd3+)-substituted cobalt-zinc ferrites(CZFs) with the form Co0.5 Zn0.5 NdxFe2 exO4(0.03≤x≤0.05) via a hydrothermal method. The as-prepared samples were thoroughly characterized using various analytical techniques. XRD, FTIR and FESEM analyses confirm the formation of a cubic spinel phase of the CZFNPs(CZF nanoparticles). A decrease in the lattice parameter due to the substitution of Fe3+by Nd3+in the lattice structures is manifested in the XRD refinement data. The magnetic properties of the proposed CZFNPs were evaluated in terms of the saturation magnetization, remanence, coercivity, squareness ratio and magnetic moment. These CZFNPs exhibit superparamagnetic behaviors at room ***, the Nd3+inclusion does not significantly affect the measured magnetizations and coercivities of the CZFNPs. Samples containing 0.01 and 0.03 Nd3+exhibit lower saturation magnetizations than that of the pristine product. The squareness ratios much less than 0.53 are ascribed to surface spin disordering. The unique magnetic traits of the synthesized CZFNPs are primarily attributed to the substitution of Fe3+ions, with smaller ionic radii, by Nd3+ions, with larger ionic radii. The proposed CZFNPs may be useful for diverse magneto-optic applications.

关键词： Spinel nanoferrites Neodymium Magnetic properties Optical properties Superparamagnetism Rare earths

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Sm^(3+)induced structural phase transition,spectral,morphological,magnetic,dielectric and impedance properties of Ni_(0.1)Cu_(0.9)Sm_(x)Fe_(2-x)O_(4) nanoferrites

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Journal of Rare Earths 2023年第11期41卷 1736-1745,I0003页

作者： K.Rajashekhar G.Vinod K.Mahesh Kumar G.Harikishan Laxman Naik J Department of Physics University College of ScienceOsmania UniversityHyderabad500007TelanganaIndia Department of Physics Kamala Institute of Technology and ScienceHuzurabad505468TelanganaIndia Department of Physics CMR College of Engineering&TechnologyHyderabad501401TelanganaIndia

In the present study,rare earth samarium(Sm^(3+))substituted Ni-Cu spinel ferrites with the composition of Ni_(0.1)Cu_(0.9)Sm_(x)Fe_(2-x)O_(4)(0≤x≤0.05 in steps of 0.01)were synthesized by using the citrate induced sol-gel auto combustion *** ferrites'structural,optical,magnetic,and dielectric studies were carried out using X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),ultraviolet-visible(UV-vis),a vibrational sample magnetometer(VSM),and an LCR *** pure Ni-Cu ferrite exhibits a tetragonal structure owing to the presence of the John Tellar ion(Cu^(2+)).XRD patterns confirm that the tetragonal structure gradually transforms into the cubic spinel structure with samarium *** nano-scale structures of these ferrites were confirmed by the average crystallite size(10.11-20.99 nm)derived from the X-ray diffraction patterns,and grain size(42.60-83.36 nm)assessed from FESEM *** existence of elements according to their chemical composition was verified by using energy dispersive X-ray(EDX)*** absorption bands(v_(1) and v_(2))detected in FTIR transmission spectra below the wavenumber of 600 cm^(-1)reveal the stretching vibrations of M-O bonds in the spinel structure at tetrahedral and octahedral *** band gap ene rgy obtained from UV absorption reveals the semiconducting nature of the *** high saturation magnetization(M_(s))is noticed at 15 K temperature for x=0.02 composition as 32.98 emu/g,while at 300 K for x=0.01composition as 27.61 emu/*** suggested cation distribution is in good agreement with observed and predicted magnetic moment values at 300 *** expected behavior of ferrites reveals the observed dielectric constant,loss tangent,and ac-conductivity values in the frequency range of 20 Hz-20 ***-Cole plots confirm that the impedance contribution is attributed to grain boundaries.

关键词： nanoferrites XRD Magnetic properties Dielectric properties Cole-cole plots Rare earths

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Synthesis and Structural Properties of Bismuth Doped Cobalt nanoferrites Prepared by Sol-Gel Combustion Method

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World Journal of Nano Science and Engineering 2015年第4期5卷 140-151页

作者： Naraavula Suresh Kumar Katrapally Vijaya Kumar Mallareddy Institute of Engineering & Technology Secunderabad India Department of Physics JNTUH College of Engineering Jagtial Nachupally (Kondagattu) Karimnagar-Dist TS India

A series of Bismuth doped Cobalt nanoferrites of chemical composition CoBixFe2-xO4 (where x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method and calcinated at 600℃. The structural and morphological studies were carried out by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infrared (FT-IR) spectra showing the single phase spinal structure. The X-ray diffraction (XRD) analysis confirmed a single phase fcc crystal. The crystallite size of all the compositions was calculated using Debye-Scherrer equation and found in the range of 17 to 26 nm. The lattice parameters were found to be decreased as Bi3+ ion doping increases. The surface morphology was studied by Scanning Electron Microscope (SEM) and particle size was confirmed by Transmission Electron Microscopy (TEM). The EDS plots revealed existence of no extra peaks other than constituents of the taken up composition. The Fourier Transform Infrared (FT-IR) studies were made in the frequency range 350 - 900 cm-1 and observed two strong absorption peaks. The frequency band is found at 596 cm-1 where as the lower frequency band at 393 cm-1. It is clearly noticed that the two prominent absorption bands were slightly shifted towards higher frequency side with the increase of Bi3+ ion concentration.

关键词： Bi-Co nanoferrites Sol-Gel Combustion Method XRD SEM EDS TEM and FTIR

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Magnetic,dielectric and electrical modulus of Ce^(3+) doped cobalt-magnesium ferrite nanoparticles

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Journal of Rare Earths 2024年第2期42卷 373-382,I0005页

作者： N.M.Basfer Hanaa Almaghamsi Department of Physics Umm AL-Qura UniversityMakkahSaudi Arabia Physics Department College of Science and ArtKing Abdulaziz UniversityPOB344Rabigh291Saudi Arabi

In this work,the magnetic,dielectric properties and electric modulus of Ce^(3+) substituted cobaltmagnesium(Co_(0.7)Mg_(0.3)Ce_(x)Fe_(2-x)O_4)(labeled as CMCF) ferrite nanoparticles were investigated in *** magnetization decreases from 50.05 to 34.87 emu/g for further substituting Ce^(3+) ***,coercivity increases from 738.22 Gs for the CMCFO sample to 912.10 Gs for the CMCF2 sample,then decreases monotonically to 762.1 Gs for the CMCF5 *** cerium content and particle size play important roles in controlling the magnetization and coercivity of the CMCF *** CMCF nanoferrites are suitable for microwave applications since their high-frequency response ranges from 7.72 to 11.07 *** CMCF nanoferrites' dielectric parameter dispersion exhibits normal *** pristine Co-Mg nanoferrite only has ε' value of 28.25,but the nanoferrite MCMF2 has ε' value of365.03,with an enhancing ratio of 1192%.The conduction mechanism of the MCMF nanoferrites was determined by fitting the σ_(ac) results via the Jonscher power *** 653 K,large polaron tunnelling is thought to be responsible for this conduction process,which is followed by electron barrier hopping at higher ***-Cole diagrams at different temperatures,assuring the contributions of the grains and their boundaries at lower temperatures(653 K) and only the grains at higher *** on our results,the CMCF nanoferrites hold magnetic and semiconducting nature,which can be used in magnetic devices and dielectrics in lower-frequencies or conductors in higher-frequencies.

关键词： nanoferrites Rare earth ions Magnetic properties Dielectric parameters Impedance spectroscopy

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Mn0.8Zn0.2Fe2O4 nanoparticulates spinel ferrites:An approach to enhance the antenna field strength for improved magnitude versus offset(MVO)

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Progress in Natural Science:Materials International 2014年第4期24卷 364-372页

作者： Majid Niaz Akhtar Nadeem Nasir Muhammad Kashif Noorhana Yahya Mukhtar Ahmad Ghulam Murtaza Muhammad Azhar Khan M.H.Asif A.Sattar R.Raza M.Saleem S.N.Khan Department of Physics COMSATS Institute of Information Technology Electrical and Electronic Engineering Department Universiti Teknologi PETRONAS Fundamental and Applied Sciences Department National Textile University Fundamental and Applied Sciences Department Universiti Teknologi PETRONAS Centre for Advanced Studies in Physics G.C.University Department of Physics The Islamia University of Bahawalpur

Electromagnetic signals in deep reservoir are very weak so that it is difficult to predict about the presence of hydrocarbon in seabed logging(SBL) *** the present work,Mn0.8Zn0.2Fe2O4 nanoferrites were prepared by a sol–gel technique at different sintering temperatures of450 °C,650 °C and 850 °C to increase the strength of electromagnetic(EM) ***,FESEM,Raman spectroscopy and HRTEM were used to analyze the phase,surface morphology and size of the *** properties of the nanoferrites were also measured using an impedance network ***,nanoferrites sintered at 850 °C with initial permeability of 200 and Q factor of 50 were used as magnetic feeders with the EM *** scale experiments were performed to investigate the effect of magnetic field strength in scale *** and MATLAB softwares were also used to confirm the oil presence in scale *** was observed that the magnitude of the EM waves for the antenna was increased up to 233%.Finally,the correlation values also show 208% increase in the magnetic field strength with the presence of the ***,antenna with Mn0.8Zn0.2Fe2O4 nanoferrites based magnetic feeders can be used for deep water and deep target hydrocarbon exploration.

关键词： nanoferrites Transmission Electron Microscopy Initial permeability Q factor Antenna

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Ion Beam Analysis and Electric Properties of GdBa2Cu3O7-δAdded with Nanosized Ferrites ZnFe2O4and CoFe2O4

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Materials Sciences and Applications 2015年第9期6卷 828-840页

作者： Hadi Basma Mohamad Roumié Ramadan Awad Salem Marhaba Mohamad Albast Ali Abualy Physics Department Faculty of Science Beirut Arab University (BAU) Beirut Lebanon Accelerator Laboratory Lebanese Atomic Energy Commission CNRS Beirut Lebanon Physics Department Faculty of Science Alexandria University Alexandria Egypt

In this study, superconducting samples of type GdBa2Cu3O7-δ added with x wt% (0 ≤ x ≤ 0.4) nanoferrites ZnFe2O4 and CoFe2O4 were prepared by the conventional solid-state reaction technique. The prepared samples were characterized using X-ray powder diffraction (XRD) in order to determine the volume fraction and lattice parameters. The elemental contents of the prepared samples were determined using particle induced X-ray emission (PIXE). In addition, the oxygen-content of these samples was obtained using non-Rutherford backscattering spectroscopy (RBS) at 3 MeV proton beam. It is found that the Oxygen-content of GdBa2Cu3O7-δ phase remains practically constant for low additions of both nanoferrites but it increases with high additions. The electrical resistivity of the prepared samples was measured by the conventional four-probe technique from room temperature down to the zero superconducting transition temperature (T0). An increase in the superconducting transition temperature Tc and the critical current density Jc is observed as x varies from 0.0 to 0.06 wt% of (ZnFe2O4)xGdBa2Cu3O7-δ, followed by a systematic decrease with increasing x. On the other hand, the Tc values for (CoFe2O4)xGdBa2Cu3O7-δ show a systematic decrease with x for both high and low additions while Jc is enhanced up to x = 0.01 wt% and decrease with further increase in x.

关键词： Gd-123 nanoferrites X-Ray Diffraction PIXE and RBS Critical Current Density

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Preparation and Characterization of MMT Doped PVA/SA Polymer Composites

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Advances in Materials Physics and Chemistry 2014年第9期4卷 172-178页

作者： Kapanigowda Hemalatha Hanumanthappa Somashekarappa Rudrappa Somashekar Department of Physics Yuvaraja’s College University of Mysore Mysore India Department of Studies in Physics University of Mysore Mysore India

Blends of PVA/SA polymer doped with Montmorillonite were prepared by solution casting technique. Doping of nanoparticles to the polymer matrix does affect the structural and conducting properties. To analyze such changes, these films were subjected to X-ray diffraction, FT-IR spectroscopy, UV-visible absorbance and impedance analysis. Microstructural parameters were computed using in-house program employing X-ray data. Electrical conductivity of these polymer composites was derived using obtained impedance values to understand the conducting property. The results thus obtained are reported in this work.

关键词： Polymer Composites X-Ray Diffraction nanoferrites

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