Impact of trivalent metal ion substitution on structural, optical, magnetic and dielectric properties of Li0.5Fe2.5O4 thin films

Chilwar, Rahul R.; Chavan, Apparao R.; Babrekar, M. K.; Jadhav, K. M.

doi:10.1016/j.physb.2019.04.031

Cited by 17 publications

(4 citation statements)

References 48 publications

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“…Diffuse reflectance spectra of calcined and sintered Li 0.5 Fe 2.5 O 4 samples were recorded to determine the optical band gap using the Kubelka−Munk theory [61,62] in which the optical band gap can be expressed by Eq. 2 [63]: assuming direct allowed as well as indirect allowed transition mechanisms [8,9,27,64]. To verify the type of transition, the exponent n can be estimated by linearization of Eq.…”

Section: Magnetic Thermoanalytic and Optical Investigationsmentioning

confidence: 99%

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

Köferstein

2020

Journal of Solid State Chemistry

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Nanocrystalline Li 0.5 Fe 2.5 O 4 was prepared by a starch-based soft-chemistry synthesis. Calcining of the (LiFe)-gel between 350 and 1000 °C results in Li 0.5 Fe 2.5 O 4 powders with crystallite sizes from 13 to 141 nm and specific surface areas between 35 and 7.1 m 2 g −1. XRD investigations reveal the formation of ordered Li 0.5 Fe 2.5 O 4. Sintering between 1050 and 1250 °C leads to ceramics with relative densities of 67−95 % consisting of grains between 0.3 and 54 µm. As the sintering temperature increases a rising weight loss of the ceramic samples was observed due to the loss of Li 2 O. Temperature-dependent magnetic measurements indicate a superparamagnetic behaviour for the nano-sized samples. Fielddependent measurements at 3 K of ceramics sintered between 1050 and 1200 °C show increasing saturation magnetization values (M s) of 70.0 to 73.0 emu g −1 most likely due to the formation of lithium vacancies and a decrease of the inversion parameter. The magnetization drops down to 67.7 emu g −1 after sintering at 1250 °C caused by the formation of hematite. Diffuse reflectance spectra reveal an indirect allowed band gap decreasing from 1.93 to 1.60 eV depending on thermal treatment. DSC measurements of the order disorder phase transition on nano-sized powders and bulk ceramics exhibit transition temperatures between Preprint 2 734 and 755 °C and enthalpy changes (∆ trs H) ranging from 5.0 to 13.5 J g −1. The linear thermal expansion coefficient was found to be 11.4⋅10 −6 K −1 .

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Section: Magnetic Thermoanalytic and Optical Investigationsmentioning

confidence: 99%

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

Köferstein

2020

Journal of Solid State Chemistry

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“…The detected structure disorder from EXAFS analysis will affect the magnetic behavior as will be shown in the discussion of the magnetic properties. Furthermore, and for determining the fine local structural parameters such as the near neighbor bond lengths of the Fe ions; the EXAFS spectrum was fitted using the theoretical structural model of Li 0.5 Fe 2.5 O 4 NPs (ICDD # 88-0671) [27]. Figure 8 explores the magnitude of FTs of EXAFS signal in k-range from 3 to 12 A ˚, across Fe K-edge along with the respective best fit of Li 0.5 Fe 2.5 O 4 NPs.…”

Section: Local/atomic Structural Study: Xafs Analysismentioning

confidence: 99%

Optimization of magnetic properties of BaTiO3/Li0.5Fe2.5O4 multiferroics prepared via modified low-temperature combustion

Imam

AbouHasswa

Ali

et al. 2022

J Mater Sci: Mater Electron

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Multiferroic (x)BaTiO3/(1 − x)Li0.5Fe2.5O4 (0.0 ≤ x ≤ 1) perovskite/spinel nanocomposite was synthesized using a modified citrate auto-combustion method. Both BaTiO3 (BTO) and Li0.5Fe2.5O4 (LFO) phases along with their composites were successfully characterized using X-ray diffraction, Fourier transformation infrared spectroscopy, and X-ray absorption fine structure spectroscopy. The nanoscale, morphology, and magnetic properties were imaged and acquired using high resolution transmission electron microscopy, atomic force microscopy, and vibrating sample magnetometer. Synchrotron radiation-based elemental selective XAFS technique was performed around Fe K-edge to obtain the selective and the detailed local structural information of Li0.5Fe2.5O4 nanoparticles (NPs). The main remarkable result in this work is the enhancement in the coercivity (HC) of LFO NPs after compositing with BTO particularly at x = 0.6, and at x = 0.8. Based on the collected results, BTO/LFO nanocomposite can be seen as a good candidate for different technological applications including magnetically modulated piezoelectric, safety rechargeable batteries, and multilayer ceramic capacitor.

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“…13). Reported optical band gaps for Li 0.5 Fe 2.5 O 4 are between 1.4 and 2.2 eV assuming direct allowed as well as indirect allowed transition mechanisms [8,9,27,64]. To verify the type of transition, the exponent n can be estimated by linearization of Eq.…”

Section: Magnetic Thermoanalytic and Optical Investigationsmentioning

confidence: 99%

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

Köferstein¹

2022

Preprint

View full text Add to dashboard Cite

Nanocrystalline Li0.5Fe2.5O4 was prepared by a starch-based soft-chemistry synthesis. Calcining of the (LiFe)-gel between 350 and 1000 °C results in Li0.5Fe2.5O4 powders with crystallite sizes from 13 to 141 nm and specific surface areas between 35 and 7.1 m2 g-1. XRD investigations reveal the formation of ordered Li0.5Fe2.5O4. Sintering between 1050 and 1250 °C leads to ceramics with relative densities of 67-95 % consisting of grains between 0.3 and 54 μm. As the sintering temperature increases a rising weight loss of the ceramic samples was observed due to the loss of Li2O. Temperature-dependent magnetic measurements indicate a superparamagnetic behaviour for the nano-sized samples. Field-dependent measurements at 3 K of ceramics sintered between 1050 and 1200 °C show increasing saturation magnetization values (Ms) of 70.0 to 73.0 emu g-1 most likely due to the formation of lithium vacancies and a decrease of the inversion parameter. The magnetization drops down to 67.7 emu g-1 after sintering at 1250 °C caused by the formation of hematite. Diffuse reflectance spectra reveal an indirect allowed band gap decreasing from 1.93 to 1.60 eV depending on thermal treatment. DSC measurements of the order disorder phase transition on nano-sized powders and bulk ceramics exhibit transition temperatures between 734 and 755 °C and enthalpy changes (trsH) ranging from 5.0 to 13.5 J g1. The linear thermal expansion coefficient was found to be 11.4x10-6 K1.

show abstract

Impact of trivalent metal ion substitution on structural, optical, magnetic and dielectric properties of Li0.5Fe2.5O4 thin films

Cited by 17 publications

References 48 publications

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

Optimization of magnetic properties of BaTiO3/Li0.5Fe2.5O4 multiferroics prepared via modified low-temperature combustion

Thermoanalytical, optical, and magnetic investigations on nanocrystalline Li0.5Fe2.5O4 and resulting ceramics prepared by a starch-based soft-chemistry synthesis

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