Dielectric, magnetic, ferroelectric, and Mossbauer properties of bismuth substituted nanosized cobalt ferrites through glycine nitrate synthesis method

Abstract

CoFe2-xBixO4 nanoferrites with x = 0, 0.05, 0.1, 0.5, and 1.0 have been synthesized by the glycine nitrate process. The present study investigates the effect of Bi3+ substitution on the microstructural, dielectric, ferroelectric, magnetic, and Mossbauer properties of CoFe2O4 nanoparticles. The X-ray diffraction technique was used to confirm the phase purity and estimate the crystallite size which revealed the formation of a secondary phase when Bi3+ concentration exceeds x = 0.5. Transmission electron microscopy indicated the formation of grains by aggregation of small crystallites with a reduction in grain size to 20 nm with an increase in Bi3+ content and also divulged the lattice parameter value to be 8.378 Å, confirming the crystalline nature of the synthesised sample. Dielectric properties performed in the frequency range of 100 Hz to 1 MHz determined that the dielectric behavior is attributed to the Maxwell-Wagner polarization and the activation energy of the specimens is calculated from the dielectric measurements. The hysteresis curve indicated the ferrimagnetic nature of the samples. The samples also exhibited a well saturated P-E loop with gradual lowering in remenant polarization, coercive field, and saturation polarization with an increase in bismuth concentration. Mössbauer spectroscopy analysis confirmed the changes in magnetic moment of ions, their coupling with neighbouring ions, and cation exchange interactions. Owing to the high physical, thermal, and chemical stabilities, these magnetic ceramics, CoFe2-xBixO4, possesses tremendous potential in major understanding of magnetism and in magnetic recording applications for high density information storage.

Structural, optical and electrical properties of Mn-doped ZnFe2O4 synthesized using sol–gel method

“…Polycrystalline ferrites were classified as good magnetic semiconductors having low electrical conductivity and eddy currents, that play an essential role in various technological applications from microwave to radio wave frequencies [1,2]. Ferrites also belong to a special class of ceramic materials that exhibit ferromagnetic nature at room temperature [3]. Among the several spinel ferrites, MFe2O4 (M=Zn, Mn, Co, Ni), ZnFe2O4 exhibits particularly intriguing features due to the diamagnetic nature of Zn 2+ and the ferrous behavior of Fe (Fe 2+ and Fe 3+ ) ions, which have highly physical and chemical stability [4].…”

DC Electrical Resistivity, Dielectric, and Magnetic Studies of Rare‐Earth (Ho3+) Substituted Nano‐Sized CoFe2O4

“…All chemicals used were purchased from Sigma–Aldrich with 99% purity. The detail experimental procedure is illustrated in our earlier publications . The final obtained powder was then calcined at 600 °C for 3 h. CFHO synthesized powder samples were X‐ray examined by Rigaku Ultima‐IV X‐Ray Diffractometer (XRD) (Cu‐K α radiation, k = 1.54 Å).…”

Visualizing the catalytic advancements in nickel ferrite via inclusion of bismuth for the removal of hazardous environmental pollutants

“…Savunthari and Shanmugam (2019) revealed that the incorporation of bismuth in zinc ferrite resulted in a decrease in crystallite size, saturation magnetisation and band-gap energy. Moreover, the tendency of bismuth ion for both the octahedral and tetrahedral sites occupancy with higher affinity for octahedral sites was anticipated by various researchers (Routray et al, 2017;Gore et al, 2017). It is readily notified in the literature that bismuth substituted nanoferrites have been employed as potential catalysts in wide-ranging reactions (Ren et al, 2016;Fesharaki et al, 2017;Kiran and Sumathi, 2017;Sumathi and Lakshmipriya, 2017).…”

“…The magnetic nature of bismuth‐doped nanoferrites endures their wide potential for memory devices and magnetic recording applications for data storage (Gore et al , 2015; Panda et al , 2015; Suresh and Vijaya, 2016; Gore et al , 2017; Routray et al , 2019). Many research cohorts have examined the electrical, magnetic, structural and optical characteristics of bismuth incorporated nanoferrites (Gore et al , 2015; Routray et al , 2017; Savunthari and Shanmugam, 2019). Panda et al (2015) observed the modification in electrical properties including increased resistivity and reduced dielectric loss with the incorporation of bismuth into cobalt ferrite lattice.…”

“…Panda et al (2015) observed the modification in electrical properties including increased resistivity and reduced dielectric loss with the incorporation of bismuth into cobalt ferrite lattice. Routray et al (2017) fabricated CoFe 2‐x Bi x O 4 ( x = 0, 0.05, 0.1, 0.5, 1.0) nanoferrites and revealed that the secondary phase formation occurred when bismuth concentration exceeded x = 0.5. Savunthari and Shanmugam (2019) revealed that the incorporation of bismuth in zinc ferrite resulted in a decrease in crystallite size, saturation magnetisation and band‐gap energy.…”