{"title":"Influence of Ni doping on microstructural, optical and dielectric properties of lanthanum-based chromite","authors":"","doi":"10.1016/j.physb.2024.416614","DOIUrl":null,"url":null,"abstract":"<div><div>In this work, LaCrO<sub>3</sub> (LCO) and LaCr<sub>0.5</sub>Ni<sub>0.5</sub>O<sub>3</sub> (LCNO) chromite samples are synthesized through sol-gel auto-combustion method. The effect of nickel content in LaCrO<sub>3</sub> is studied with respect to their structural, optical and dielectric properties. X-ray diffraction (XRD) confirmed the single-phase orthorhombic crystal structure with space group (<em>Pnma</em>) of both the samples. The obtained lattice parameters and bond lengths via Rietveld refinement analysis are found to be increased with Ni content. The crystallite sizes of LCO and LCNO are calculated using Scherrer's equation, which are found to be 22 nm and 28 nm, respectively. The Fourier-transform infrared (FTIR) spectroscopy of both the samples confirmed the different functional groups and having two main characteristic bands at 420 and 620 cm<sup>−1</sup>. Scanning electron microscopy (SEM) shows the variation in the surface morphology with Ni doping. Energy-dispersive X-ray (EDX) spectroscopy confirm the elemental compositions of the samples with their nominal atomic and weight percentages. UV–Visible spectroscopy reveals the decrease in the band gap energy from 2.60 eV to 2.30 eV with Ni doping. Raman spectra of LCO and LCNO samples, confirmed the formation of single-phase orthorhombic structure. The Raman active modes are also shifted with Ni doping due to lattice strain and crystal defects. Photoluminescence (PL) absorption intensities are varied, which is due to the creation of defects with Ni doping in LCO crystal structure. The electronic states of constituent element are obtained using X-ray photoelectron spectroscopy (XPS). Dielectric constant (εʹ), loss, and a.c. conductivity (σ<sub>ac</sub>) are studied based on the Ni<sup>2+</sup>/Ni<sup>3+</sup> substitution in LCO at Cr site.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physica B-condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921452624009554","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
In this work, LaCrO3 (LCO) and LaCr0.5Ni0.5O3 (LCNO) chromite samples are synthesized through sol-gel auto-combustion method. The effect of nickel content in LaCrO3 is studied with respect to their structural, optical and dielectric properties. X-ray diffraction (XRD) confirmed the single-phase orthorhombic crystal structure with space group (Pnma) of both the samples. The obtained lattice parameters and bond lengths via Rietveld refinement analysis are found to be increased with Ni content. The crystallite sizes of LCO and LCNO are calculated using Scherrer's equation, which are found to be 22 nm and 28 nm, respectively. The Fourier-transform infrared (FTIR) spectroscopy of both the samples confirmed the different functional groups and having two main characteristic bands at 420 and 620 cm−1. Scanning electron microscopy (SEM) shows the variation in the surface morphology with Ni doping. Energy-dispersive X-ray (EDX) spectroscopy confirm the elemental compositions of the samples with their nominal atomic and weight percentages. UV–Visible spectroscopy reveals the decrease in the band gap energy from 2.60 eV to 2.30 eV with Ni doping. Raman spectra of LCO and LCNO samples, confirmed the formation of single-phase orthorhombic structure. The Raman active modes are also shifted with Ni doping due to lattice strain and crystal defects. Photoluminescence (PL) absorption intensities are varied, which is due to the creation of defects with Ni doping in LCO crystal structure. The electronic states of constituent element are obtained using X-ray photoelectron spectroscopy (XPS). Dielectric constant (εʹ), loss, and a.c. conductivity (σac) are studied based on the Ni2+/Ni3+ substitution in LCO at Cr site.
期刊介绍:
Physica B: Condensed Matter comprises all condensed matter and material physics that involve theoretical, computational and experimental work.
Papers should contain further developments and a proper discussion on the physics of experimental or theoretical results in one of the following areas:
-Magnetism
-Materials physics
-Nanostructures and nanomaterials
-Optics and optical materials
-Quantum materials
-Semiconductors
-Strongly correlated systems
-Superconductivity
-Surfaces and interfaces