Dielectric and optical properties of Ni-doped LaFeO3 nanoparticles

Abstract

Un-doped and Ni-doped lanthanum ferrite nanoparticles were synthesized by solid-state method. Ni concentrationdependent structural, dielectric and optical properties of synthesized nanoparticles were investigated. X-ray diffraction patterns confirmed predominant single-phase orthorhombic crystal structure with space group Pbnm in all samples. Average crystallite size was found to vary from 19 to 21 nm with Ni concentration. The field emission scanning electron microscopy revealed nanocrystalline structure with homogenous distribution of particles. UV-Vis-NIR diffuse spectra captured at room temperature indicate that La 1−x Ni x FeO 3 is an indirect band gap material. The band gap varies from 1.70 to 1.85 eV with changing Ni concentration. Frequency-dependent dielectric constant, dielectric loss and ac conductivity were studied at room temperature. The dielectric constant was found to increase with increasing Ni content at high frequency. The loss factor resulted from domain wall resonance exhibited an identical dispersion behavior of dielectric constant. At high frequencies, the dielectric losses of orthoferrites were found to be low. This is attributed to the restricted motion of domain wall pointing its plausible practical applications in magnetically tunable filters and oscillators.

Mechanical behavior, enhanced dc resistivity, energy band gap and high temperature magnetic properties of Y-substituted Mg–Zn ferrites

“…The room temperature dc electrical resistivity (r RT ) of Mg 0.5 Zn 0.5 Y r RT is noted to increased due to Y substitution unlike for x=0.01 ( figure 8(a)), can be explained by Verwey mechanism based on electrons exchange involving the ions of the element with different valence states positioned octahedral (B-site) [79,80]. In the present case, the Fe 2+ and Fe 3+ is responsible for the conduction because of the hopping tendency between them [81,82] and the Fe 2+ ions are the product of sintering process [42]. The value of r RT is found to be 0.45×10 5 Ω cm for x=0.00 and 0.40×10 5 Ω cm, 1.57×10 6 Ω cm, 1.78×10 6 Ω cm, 2.19×10 6 Ω cm and 1.43×10 6 Ω cm for x=0.01, 0.02, 0.03, 0.04 and 0.05, respectively.…”

“…High resistivity of ferrites is essential for most electronic application and therefore, the study of dc electrical resistivity is important for prediction of their application in electronic and high In the present case, the Fe 2+ and Fe 3+ is responsible for the conduction because of the hopping tendency between them [83,84] and the Fe 2+ ions are the product of sintering process [42]. The value of 𝜌 𝑅𝑇 is found to be 0.45 × 10 5 Ω-cm for x = 0 and 0.40 × 10 5 Ω-cm, 1.57 × 10 6 Ω-cm, 1.78 × 10 6 Ω-cm, 2.19 × 10 6 Ω-cm and 1.43 × 10 6 Ω-cm for x = 0.01, 0.02, 0.03, 0.04 and 0.05, respectively.…”

La0.8Bi0.2FeO3 Perovskite-Type: High-Performance of Photocatalytic Degradation of Ortho-Toluidine Blue Under Visible Light Irradiation

“…However, E g values decrease to 1.86, 1.76, and1.54 eV, respectively, for Bi substitutions of 20, 40, and 60%. Furthermore, the value of E g can be decreased through Fe-O octahedral restructuring of molecular orbitals and nanoparticles length scale [42][43][44]. This reduction could also be attributed to the direct energy transfer occurring between the excited states of the semiconductor and the 3d levels of Bi 3+ ions [45].…”

Evaluación y efecto de sinterizado sobre las propiedades de la ferrita de lantano-níquel

“…Tal como se observa en los difractogramas se confirma que, con el método de síntesis utilizado, se logra obtener exitosamente LaFe0.9Ni0.1O3 sin la presencia de fases secundarias siendo consistente para todas las temperaturas analizadas. Adicionalmente todos los picos de difracción se identificaron con la LaFeO3 de estructura ortorrómbica (COD 1526450) y grupo espacial Pbnm (62), lo cual es congruente con diversos autores (Matin et al 2019). La obtención de la ferrita de lantano sin fases secundarias para todas las temperaturas se atribuye a que la activación de los óxidos precursores, mediante molienda de alta energía, ha mostrado ser un método efectivo para reducir la temperatura para la síntesis de cerámicos avanzados (Bolarín et al 2007).…”