含有纳米晶TiO和石墨烯相关材料的混合纳米复合材料的磁共振研究。

Magnetic Resonance Studies of Hybrid Nanocomposites Containing Nanocrystalline TiO and Graphene-Related Materials.

作者信息

Guskos Nikos, Zolnierkiewicz Grzegorz, Kusiak-Nejman Ewelina, Guskos Aleksander, Aidinis Konstantinos, Bobrowska Marta, Berczynski Paweł, Wanag Agnieszka, Pelech Iwona, Narkiewicz Urszula, Morawski Antoni W

机构信息

Department of Physics, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology in Szczecin, al. Piastow 48, 70-311 Szczecin, Poland.

Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian of Technology in Szczecin, Pulaskiego 10, 70-322 Szczecin, Poland.

出版信息

Materials (Basel). 2022 Mar 18;15(6):2244. doi: 10.3390/ma15062244.

DOI:10.3390/ma15062244

PMID:35329696

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8949220/

Abstract

Nanocomposites based on nanocrystalline titania modified with graphene-related materials (reduced and oxidized form of graphene) showed the existence of magnetic agglomerates. All parameters of magnetic resonance spectra strongly depended on the materials' modification processes. The reduction of graphene oxide significantly increased the number of magnetic moments, which caused crucial changes in the reorientation and relaxation processes. At room temperature, a wide resonance line dominated for all nanocomposites studied and in some cases, a narrow resonance line derived from the conduction electrons. Some nanocomposites (samples of titania modified with graphene oxide, prepared with the addition of water or butan-1-ol) showed a single domain magnetic (ferromagnetic) arrangement, and others (samples of titania modified with reduced graphene oxide) exhibited magnetic anisotropy. In addition, the spectra of EPR from free radicals were observed for all samples at the temperature of 4 K. The magnetic resonance imaging methods enable the capturing of even a small number of localized magnetic moments, which significantly affects the physicochemical properties of the materials.

摘要

基于用石墨烯相关材料（还原态和氧化态石墨烯）改性的纳米晶二氧化钛的纳米复合材料显示出磁性团聚体的存在。磁共振谱的所有参数都强烈依赖于材料的改性过程。氧化石墨烯的还原显著增加了磁矩的数量，这导致了重新取向和弛豫过程的关键变化。在室温下，对于所有研究的纳米复合材料，宽共振线占主导，在某些情况下，窄共振线源自传导电子。一些纳米复合材料（添加水或丁醇制备的用氧化石墨烯改性的二氧化钛样品）呈现单畴磁性（铁磁性）排列，而其他一些（用还原氧化石墨烯改性的二氧化钛样品）表现出磁各向异性。此外，在4 K温度下对所有样品都观察到了自由基的电子顺磁共振谱。磁共振成像方法能够捕捉到即使少量的局部磁矩，这对材料的物理化学性质有显著影响。