Magnetopolymers are of interest in smart material applications; however, changing their magnetic properties post synthesis is complicated. In this study, we introduce easily programmable polymer magnetic composites comprising 2D lattices of droplets of solid-liquid phase change material, with each droplet containing a single magnetic dipole particle. These composites are ferromagnetic with a Curie temperature defined by the rotational freedom of the particles above the droplet melting point. We demonstrate magnetopolymers combining high remanence characteristics with Curie temperatures below the composite degradation temperature. We easily reprogram the material between four states: (1) a superparamagnetic state above the melting point which, in the absence of an external magnetic field, spontaneously collapses to; (2) an artificial spin ice state, which after cooling forms either; (3) a spin glass state with low bulk remanence, or; (4) a ferromagnetic state with high bulk remanence when cooled in the presence of an external magnetic field. We observe the spontaneous emergence of 2D magnetic vortices in the spin ice and elucidate the correlation of these vortex structures with the external bulk remanence. We also demonstrate the easy programming of magnetically latching structures.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9722694 | PMC |
http://dx.doi.org/10.1038/s41378-022-00463-2 | DOI Listing |
ACS Appl Mater Interfaces
December 2024
Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Boron (B)-substituted wurtzite AlN (AlBN) is a recently discovered wurtzite ferroelectric material that offers several advantages over ferroelectric HfZrO and PbZrTiO. Such benefits include a relatively low growth temperature as well as a thermally stable, and thickness-stable ferroelectric polarization; these factors are promising for the development of ferroelectric nonvolatile random-access memory (FeRAM) that are CMOS-compatible, scalable, and reliable for storing data in harsh environments. However, wurtzite ferroelectric materials may undergo exacerbated self-heating upon polarization switching relative to other ferroelectric materials; the larger energy loss is anticipated due to the higher coercive field and remanent polarization.
View Article and Find Full Text PDFNanomaterials (Basel)
November 2024
Ioffe Institute, 194021 St. Petersburg, Russia.
Adv Mater
December 2024
Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
Nanoscale
November 2024
Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark.
Shape-controlled precursors enable grain alignment without using an applied magnetic field in the permanent magnet material strontium hexaferrite. The effect is investigated by conducting four series of experiments using different compaction methods: two cold and two hot compactions. The hypothesis is that magnetic short-circuiting will diminish the grain alignment (texture) in cold compacted samples.
View Article and Find Full Text PDFHeliyon
October 2024
Department of Oil and Gas Engineering, Faculty of Earth science, University of Miskolc, Miskolc, Hungary.
In recent decades, the rising demand for permanent magnetic materials has driven manufacturers to explore substitutes for rare earth elements in response to their fluctuating prices and negative environmental impact. M-type hexaferrites considered as good alternatives and studies have focused on enhancing their magnetic and structural properties through various approaches. In this study, new approach using low heating rate microwave sintering has been applied to investigate the changes on density, microstructure, and magnetic properties of strontium hexaferrite from core to surface.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!