Synthesis, Structural, Magnetic, Dielectric and Optical Properties of Co Doped Cr-Zn Oxide Nanoparticles for Spintronic Devices

Abstract

Dilute magnetic semiconductor (DMS) nanoparticles of Co doped Zn0.95Cr0.05O were synthesized by sol-gel auto-combustion technique. Crystallographic analysis was made by using X-ray diffraction (XRD) technique. Rietveld refined X-ray diffraction patterns confirm the single phase wurtzite type crystal structure with space group p63mc. Replacement of larger Zn 2+ ions by smaller Co 2+ reduces the lattice parameters 'a' and 'c'. Average crystallite estimated from Scherrer equation is found increasing from 17.6 to 22.0 nm with the addition of Co 2+ ions.Scanning electron micrographs (SEM) were used to understand the surface morphology of the samples. Average grain size obtained from SEM analysis is observed in the range 22.1 to 26.5 nm. Enriched ferromagnetism is observed for Co 2+ doped samples and the saturation magnetization increases from 0.0514 to 0.1026 emu/gm. At lower frequency region both dielectric constant () and dielectric loss tangent (tan ) have higher values and decreases with increasing frequency and becomes almost constant at higher frequency region. Energy band gap (Eg) is decreases from 3.26 to 2.69 eV with the addition of Co 2+ ions in Zn-Cr oxides. Enriched ferromagnetism and higher dielectric constant at low frequency make these materials suitable for spintronic devices.

Effect of hydrophobic nano‐silica/β‐nucleating agent on the crystallization behavior and mechanical properties of polypropylene random copolymers

“…Nanoparticles have quantum size effect, small size effect, surface effect and macroscopic quantum effect. [21][22][23][24][25][26][27] Adding a small amount to PP-R can change the material properties. Due to the characteristics of high modulus and high rigidity, hydrophobic nano-SiO 2 can be used to improve the strength and scratch resistance of composite materials.…”

“…Therefore, it is necessary to add nanoparticles while adding the nucleating agent. Nanoparticles have quantum size effect, small size effect, surface effect and macroscopic quantum effect 21–27 . Adding a small amount to PP‐R can change the material properties.…”

Oxide nanoparticle exsolution in Lu-doped (Ba,La)CoO3

“…It should be highlighted that the presence of nanoparticles and other nanostructures has a greater area of applications than proton-conducting fuel cells, i.e. in spintronic devices, 37 supercapacitors, 38 detectors of biomolecules, 39,40 or in wastewater purification solutions. 41,42 Furthermore, surface functionalization plays a crucial role, and it can be achieved, among others, by doping with various elements.…”

Oxidation-Resistant Metallic Bismuth Nanoparticles for Electrically Conductive Adhesives

“…Over the past two decades, the remarkable progress and vast potential of metal nanoparticles and metal oxide nanoparticles have become increasingly evident as they assume pivotal roles in a wide array of applications. − These nanoparticles have emerged as indispensable components for various purposes, such as imaging, sensing, and the creation of stretchable electrodes, further highlighting their significance in advancing biomedical and flexible electronics domains. − Metallic bismuth (Bi) nanoparticles have attracted much attention over the past few years due to their attractive properties. Bi nanoparticles, non-toxic and cheap diamagnetic heavy metal nanomaterials, can be widely used in near-infrared absorption, X-ray attenuation, and photothermal conversion due to their adjustable band gap, unique structure, and high-performance physical and chemical properties. − …”