Characterization of SrCo 1.5 Ti 1.5 Fe 9 O 19 hexagonal ferrite synthesized by sol-gel combustion and solid state route

Vinaykumar, R.; Mazumder, R.; Bera, J.

doi:10.1016/j.jmmm.2016.12.135

Cited by 25 publications

(9 citation statements)

References 36 publications

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“…The first weight-loss step occurred below approximately 350 • C and can be attributed to the combustion of residual organic acids and the pyrolysis of NO 3 − and organic phases to give an amorphous inorganic phase [5,32]. The second weight-loss step was due to the further transformation of amorphous inorganic phase into crystalline inorganic phase [33]. Additionally, in the DSC curves, the first weight-loss step was accompanied by a strong exothermic peak, which was centered at 262, 327, 277 and 297 • C, respectively.…”

Section: Tg-dsc Resultsmentioning

confidence: 99%

Effect of Small Molecular Organic Acids on the Structure and Catalytic Performance of Sol–Gel Prepared Cobalt Cerium Oxides towards Toluene Combustion

et al. 2019

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Cobalt cerium oxide catalysts with small molecular organic acids (SOAs) as chelating agents were prepared via the sol–gel method and investigated for the complete oxidation of toluene. Four kinds of natural SOAs, i.e. malic acid (MA), citric acid (CA), glycolic acid (GA), and tartaric acid (TA), were selected. The effect of organic acids on the composition, structure, morphology and catalytic performance of metal oxides is discussed in details. The cobalt cerium oxides catalysts were characterized by various techniques, including TG–DSC, XRD, SEM–EDS, N2–adsorption and desorption, XPS, and H2–TPR analyses. The results show that the nature of organic acids influenced the hydrolysis, condensation and calcination processes, as well as strongly affected the textural and physicochemical properties of the metal oxides synthesized. The best catalytic activity was obtained with the CoCe–MA catalyst, and the toluene conversion reached 90% at 242 °C. This outstanding catalytic activity could be related to its textural, redox properties and unique surface compositions and oxidation states. In addition, the CoCe–MA catalyst also showed excellent stability in long–time activity test.

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Section: Tg-dsc Resultsmentioning

confidence: 99%

Effect of Small Molecular Organic Acids on the Structure and Catalytic Performance of Sol–Gel Prepared Cobalt Cerium Oxides towards Toluene Combustion

et al. 2019

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“…The FTIR spectra show the characteristic peaks in the required region, which are 1413, 815.25, 542.71 and 432.48 cm −1 . From Figure 3a, it can be seen that the FTIR characteristics transmittance absorption peak at 1413 cm −1 was attributed to C–O stretching, CH 2 stretching, and C=O [51,52]. The absorption bands at 815.25 cm −1 and 728.12 cm −1 were assigned to the N–O bending vibration of NO 3 − , and to C–N stretching from the ammonium nitrate used in the reaction.…”

Section: Resultsmentioning

confidence: 99%

“…The absorption bands at 815.25 cm −1 and 728.12 cm −1 were assigned to the N–O bending vibration of NO 3 − , and to C–N stretching from the ammonium nitrate used in the reaction. [51,52,53].…”

Section: Resultsmentioning

confidence: 99%

Effect of Ratio in Ammonium Nitrate on the Structural, Microstructural, Magnetic, and AC Conductivity Properties of BaFe12O19

et al. 2018

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This paper investigates the effect of the ratio of ammonium nitrate (AN) on the structural, microstructural, magnetic, and alternating current (AC) conductivity properties of barium hexaferrite (BaFe12O19). The BaFe12O19 were prepared by using the salt melt method. The samples were synthesized using different powder-to-salt weight ratio variations (1:3, 1:4, 1:5, 1:6 and 1:7) of BaCO3 + Fe2O3 and ammonium nitrate salt. The NH4NO3 was melted on a hot plate at 170 °C. A mixture of BaCO3 and Fe2O3 were added into the NH4NO3 melt solution and stirred for several hours using a magnetic stirrer under a controlled temperature of 170 °C. The heating temperature was then increased up to 260 °C for 24 hr to produce an ash powder. The x-ray diffraction (XRD) results show the intense peak of BaFe12O19 for all the samples and the presence of a small amount of the impurity Fe2O3 in the samples, at a ratio of 1:5 and 1:6. From the Fourier transform infra-red (FTIR) spectra, the band appears at 542.71 cm−1 and 432.48 cm−1, which corresponding to metal–oxygen bending and the vibration of the octahedral sites of BaFe12O19. The field emission scanning electron microscope (FESEM) images show that the grains of the samples appear to stick each other and agglomerate at different masses throughout the image with the grain size 5.26, 5.88, 6.14, 6.22, and 6.18 µm for the ratios 1:3, 1:4, 1:5, 1:6, and 1:7 respectively. From the vibrating sample magnetometer (VSM) analysis, the magnetic properties of the sample ratio at 1:3 show the highest value of coercivity Hc of 1317 Oe, a saturation magnetization Ms of 91 emu/g, and a remnant Mr of 44 emu/g, respectively. As the temperature rises, the AC conductivity is increases with an increase in frequency.

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“…The substitution of doping metal ions in the parent material can greatly enhance or tune the intrinsic magnetic properties of the material making them suitable for specific applications. In order to further enhance the magnetic and electric properties of M-type hexaferrites, several researches have been conducted by replacing the Fe 3+ ions by the various rare earth ions such as gadolinium (Gd) [6], neodymium (Nd) [7] as well as various divalent (Co 2+ , Mg 2+ ) and tetravalent (Ti 4+ , Sn 4+ , Zr 4+ ) cations [8]. Within the family of hexaferrites, the M-type hexaferrite has smaller Fe 3+ ions occupying the interstitial sites whereas the bigger ions Sr, Ba and oxides positioned inside the crystal lattice imparting a denser crystal structure [3].…”

Section: Introductionmentioning

confidence: 99%

“…Within the family of hexaferrites, the M-type hexaferrite has smaller Fe 3+ ions occupying the interstitial sites whereas the bigger ions Sr, Ba and oxides positioned inside the crystal lattice imparting a denser crystal structure [3]. Among the M-type hexaferrites, the strontium hexaferrites are found to have higher values of saturation magnetization (Ms = 74-92 emu/g) and large magnetocrystalline anisotropy [8]. The crystal structure of M-type hexaferrites is represented by the P63/mmc space group, 24 Fe 3+ ions occupying the five sites naming, three octahedral (12k, 4f2, and 2a), one tetrahedral (4f1) and one trigonal bipyramidal (2b) site [8].…”

Section: Introductionmentioning

confidence: 99%

Yttrium doped strontium nano hexaferrites: Influence of yttrium on the structural and magnetic properties of sol-gel synthesized nanocrystalline strontium hexaferrite

Sharma¹,

Kumar

Gewali

et al. 2022

J. Phys.: Conf. Ser.

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Yttrium (Y3+)-substituted strontium hexaferrite nanoparticles with composition SrFe12-x Y x O19 have been synthesized using the sol-gel method. Diverse analytical tools have been applied to characterize the prepared strontium hexaferrite nanoparticles and to analyse the influence of yttrium (Y3+) substitution on the structural and magnetic properties. X-ray diffraction patterns confirm the presence of single phase M-type hexagonal crystalline structure. In fourier-transform infrared spectroscopy, the absorption bands at low wavenumber confirmed the formation of hexagonal ferrites. The vibrating sample magnetometer has been employed to study the magnetic behavior of Y3+ ions substituted strontium hexaferrite. The decrease in saturation magnetization (Ms) and coercivity (Hc) value has been explained on the basis of alteration in magnetic interactions due to the replacement of both Fe3+ ions by the non-magnetic Y3+ ions.

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Characterization of SrCo 1.5 Ti 1.5 Fe 9 O 19 hexagonal ferrite synthesized by sol-gel combustion and solid state route

Cited by 25 publications

References 36 publications

Effect of Small Molecular Organic Acids on the Structure and Catalytic Performance of Sol–Gel Prepared Cobalt Cerium Oxides towards Toluene Combustion

Effect of Small Molecular Organic Acids on the Structure and Catalytic Performance of Sol–Gel Prepared Cobalt Cerium Oxides towards Toluene Combustion

Effect of Ratio in Ammonium Nitrate on the Structural, Microstructural, Magnetic, and AC Conductivity Properties of BaFe12O19

Yttrium doped strontium nano hexaferrites: Influence of yttrium on the structural and magnetic properties of sol-gel synthesized nanocrystalline strontium hexaferrite

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