Material functionalities strongly depend on the stoichiometry, crystal structure, and homogeneity. Here we demonstrate an approach of amorphous nonstoichiometric inhomogeneous oxides to realize tunable ferromagnetism and electrical transport at room temperature. In order to verify the origin of the ferromagnetism, we employed a series of structural, chemical, and electronic state characterizations. Combined with electron microscopy and transport measurements, synchrotron-based grazing incident wide angle X-ray scattering, soft X-ray absorption and circular dichroism clearly reveal that the room-temperature ferromagnetism originates from the InCoO amorphous phase with a large tunable range of oxygen vacancies. The room-temperature ferromagnetism is tunable from a high saturation magnetization of 500 emu cm to below 25 emu cm, with the evolving electrical resistivity from 5 × 10 μΩ cm to above 2.5 × 10 μΩ cm. Inhomogeneous nano-crystallization emerges with decreasing oxygen vacancies, driving the system towards non-ferromagnetism and insulating regime. Our work unfolds the novel functionalities of amorphous nonstoichiometric inhomogeneous oxides, which opens up new opportunities for developing spintronic materials with superior magnetic and transport properties.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.scib.2020.06.035 | DOI Listing |
ACS Appl Mater Interfaces
April 2024
Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
Pathological calcifications, especially calcium phosphate microcalcifications (MCs), appear in most early breast cancer lesions, and their formation correlates with more aggressive tumors and a poorer prognosis. Hydroxyapatite (HA) is a key MC component that crystallizes in the tumor microenvironment. It is often associated with malignant breast cancer lesions and can trigger tumorigenesis .
View Article and Find Full Text PDFJ Chem Phys
March 2024
CNRS, Laboratoire ICube, Université de Strasbourg, UMR 7357, F-67037 Strasbourg, France.
First-principles molecular dynamics combined with the approach-to-equilibrium molecular dynamics methodology is employed to calculate the thermal conductivity of non-stoichiometric amorphous SiN. This is achieved by implementing thermal transients in five distinct models of different sizes along the direction of the heat transport. Such models have identical structural features and are representative of the same material, thereby allowing for a reliable analysis of thermal conductivity trends as a function of the relevant cell dimension.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2023
NANOTECH Centre, Ural Federal University, 19 Mira St., 620002 Yekaterinburg, Russia.
Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronic devices. They possess a unique combination of physical and chemical properties, such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric HfO nanotubes.
View Article and Find Full Text PDFChem Sci
November 2023
Zhejiang Provincial Key Laboratory of Water Science and Technology, Yangtze Delta Region Institute of Tsinghua University, Zhejiang Jiaxing 314006 P. R. China
Nickel-iron (oxy)hydroxides (NiFeOH) have been validated to speed up sluggish kinetics of the oxygen evolution reaction (OER) but still lack satisfactory substrates to support them. Here, non-stoichiometric blue titanium oxide (B-TiO) was directly derived from Ti metal by alkaline anodization and used as a substrate for electrodeposition of amorphous NiFeOH (NiFe/B-TiO). The performed X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations evidenced that there is a charge transfer between B-TiO and NiFeOH, which gives rise to an elevated valence at the Ni sites (average oxidation state ∼ 2.
View Article and Find Full Text PDFMater Horiz
November 2023
State Key Laboratory of Silicon and Advanced Semiconductor Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Amorphous oxides show great prospects in revolutionizing memristors benefiting from their abundant non-stoichiometric composition. However, an in-depth investigation of the memristive characteristics in amorphous oxides is inadequate and the resistive switching mechanism is still controversial. In this study, aiming to clearly understand the gradual conductance modulation that is deeply bound to the evolution of defects-mainly oxygen vacancies, forming-free memristors based on amorphous ZnAlSnO are fabricated, which exhibit high reproducibility with an initial low-resistance state.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!