Raman spectra of sol-gel auto-combustion synthesized Mg-Ag-Mn and Ba-Nd-Cd-In ferrite based nanomaterials

Structural elucidation and dielectric behavior evaluation of sol-gel synthesized Co-Al co-substituted M-type hexaferrite materials

In the present review paper, we have explained the structure of Y-type hexagonal ferrite and various synthesis techniques. This paper also includes structural, electrical, magnetic properties and applications of Y-type hexaferrites and focusses on their use in antenna applications and microwave absorbing characteristic materials. Ferromagnetic nature of hexaferrites cause the induction of magnetisation within the crystal structure, which divide them into two groups: First with easy axis of magnetisation is known as uniaxial hexaferrites and second is known as ferroxplana having easy plane of magnetisation. The excellent magnetic properties of Y-type ferrites make them useful in the devices operating at high frequency range. The persistence of high refractive index upto 1 GHz enables these hexagonal ferrites useful in UHF antenna designs with small dimensions. The doping in Y-type hexaferrites affect all the properties. Current developments in Y-type hexaferrites will be explained in detail in the review of literature related to Y-type hexaferrites for the last 25 years, i.e. from 1994 to 2019 in this review paper.

A review on structural, electrical and magnetic properties of Y-type hexaferrites synthesized by different techniques for antenna applications and microwave absorbing characteristic materials

A series of unmodified and copper-modified zinc‑magnesium nanoferrites [Zn0.7Mg0.3-xCuxFe2O4 (x = 0.0, 0.02, 0.04, 0.06)] were prepared to degrade methylene blue (MB), a widely used textile dye and a threat to humans and the environment. The X-ray diffraction data reveals a spinel cube-like crystal structure with no additional phases. The sharpness and frequency of XRD peaks highlighted the nanocrystalline structure of fabricated photocatalysts. The calculated crystallite size (t) shows inconsistent behavior within 13–25 nm on doping copper ions within the crystal matrix of Zn-Mg nanoferrites. The morphological analysis showed the existence of spherical and aggregated nanoparticles for the synthesized Zn0.7Mg0.3Fe2O4 (x = 0.0), and Zn0.7Mg0.28Cu0.02Fe2O4 (x = 0.02) specimens. In the fabrication of Zn0.7Mg0.3Fe2O4 (ZMF1), Zn0.7Mg0.28Cu0.02Fe2O4 (ZMF2), Zn0.7Mg0.26Cu0.04Fe2O4 (ZMF3) and Zn0.7Mg0.24Cu0.06Fe2O4 (ZMF4) nanoferrites, the predicted band gaps were 2.30 eV, 2.18 eV, 2.07 eV, and 1.94 eV, respectively. The FTIR spectrum shows stretching vibrations in Fe-O complexes at the A-sites and B-sites, whereas the Raman spectrum exhibits five Raman active vibrational modes at 230–800 cm−1. The nanophotocatalysts showed excellent magnetization values around 4.44–12.92 emu/g with an applied field of 6000 Oe. In the photocatalytic degradation of methylene blue, Zn0.7Mg0.24Cu0.06Fe2O4 (x = 0.06) nanophotocatalyst showed a maximum rate constant of 0.0252 min−1 and 90% photocatalytic degradation efficiency. The nanoferrites showed excellent photocatalytic activity for five cycles and were easily separated using an external magnet. 

Photocatalytic dye degradation efficiency and reusability of Cu-substituted Zn-Mg spinel nanoferrites for wastewater remediation

Sol-gel synthesized Ba-Nd-Cd-In nanohexaferrites for high frequency and microwave devices applications

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

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

Z-type nanohexaferrites has attracted substantial attention in the field of materials science especially in the research areas of high frequency and microwave devices applications due to their excellent magnetic properties in comparison with the spinel ferrites. A series of Ba1.5Sr1.5Co2−xYxMnyNizFe24−y−zO41 (x = 0.0, 0.05, 0.10, 0.15, 0.20; y = z = 0.0, 0.25, 0.50, 0.75, 1.00) Z-type hexaferrites were fabricated with the help of sol–gel auto-combustion method in order to achieve its better microstructural and magnetic properties. The crystallographic structure of prepared specimens was characterized by XRD which revealed the presence of Z-type single-phase hexagonal structure with some additional phases accompanied by P63/mmc space group. The average particle size calculated by Scherrer formula was found to be in the range of 40–55 nm. The FTIR spectrum of synthesized specimens was observed in the range of 400–600 cm−1 which confirms our microstructural results to a great extent. From the M–H hysteresis loops, magnetic parameters such as saturation magnetization (Ms) (44.04–35.59 emu/g) and coercivity (Hc) (42.3–248.96 Oe) were measured and it was observed that the synthesized specimens exhibit excellent characteristics of soft ferrite which make it suitable for the multilayer chip inductors, electromagnets, and magnetic storage devices applications.

A study of magnetic properties of Y–Ni–Mn substituted Co2Z-type nanohexaferrites via vibrating sample magnetometry

A series of the Y-type hexaferrites having chemical composition Sr2-xDyxCo2NiyFe12-yO22 (x = 0.0, 0.01, 0.02, 0.03, 0.04 and y = 0.0, 0.1, 0.2, 0.3, 0.4) were fabricated with doping of Dy3+ and Ni2+. XRD patterns confirm the formation of a single-phase hexagonal structure along with some impurity phases. FESEM and TEM analysis shows the formation of agglomerated magnetic nanoparticles. M − H loops obtained from VSM observations were used to study the magnetic parameters viz. saturation magnetization (Ms = 34.285–44.782 emu/g), remanence (Mr = 1.080–11.819 emu/g) and coercivity (Hc = 33.976–246.052 Oe), which were found to increase with an increase in Dy3+/Ni2+ substituents. The synthesized materials with excellent structural and magnetic properties are promising candidates for high-frequency applications.

Fabrication of Ni2+ and Dy3+ substituted Y-Type nanohexaferrites: A study of structural and magnetic properties

Structural, magnetic and Mössbauer analysis of lanthanum and nickel doped Co2Y-type hexaferrite nanomaterial matrix synthesized by sol-gel auto-combustion technique

Monika Chandel

Papers

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

A review on structural, electrical and magnetic properties of Y-type hexaferrites synthesized by different techniques for antenna applications and microwave absorbing characteristic materials

A study of magnetic properties of Y–Ni–Mn substituted Co2Z-type nanohexaferrites via vibrating sample magnetometry

Fabrication of Ni2+ and Dy3+ substituted Y-Type nanohexaferrites: A study of structural and magnetic properties

Structural, magnetic and Mössbauer analysis of lanthanum and nickel doped Co2Y-type hexaferrite nanomaterial matrix synthesized by sol-gel auto-combustion technique