Bulk magnetic properties arise from micron-sized supraparticle interactions and can be modified on the nanoscale

This data publication is based on the metadata and datasets underlying the manuscript: Bulk magnetic properties arise from micron-sized supraparticle interactions and can be modified on the nanoscale Magnetic supraparticles (SPs) can be employed as micron-sized particulate additives in arbitrary objects to serve as ID-tag or recorder of environmental triggers. Combined with magnetic particle spectroscopy (MPS), that enables read-out of the magnetic information in ambient conditions within seconds, magnetic SPs represent a powerful approach to equip materials with information. The encoded information relies on magnetic interactions within the SPs (intra-SP interactions) of chosen NPs. However, possible magnetic interactions between SPs (inter-SP interactions), that might alter the MPS signal as well, have been neglected so far. Herein, it is elucidated that significant inter-SP interactions exist and that they can be tailored via adjustments in the SP structure, i.e. by defined adjustments of their intra-interaction as revealed by 3D-MuMax simulations and experiments in viscous fluids. Superparamagnetic iron oxide nanoparticle-based SP powders with strong inter-SP interactions exhibit significantly different MPS signals compared to their state after being incorporated into a matrix. Powders with weak inter-SP interactions (achieved by integration of non-magnetic SiO2 nanoparticles) show almost no signal change before and after incorporation. Both extremes of inter-SP interactions can be beneficial for various application scenarios and can be tailored on the nano-scale due to the interdependency of intra- and inter-SP interactions.本数据集出版物依托于下述研究论文的元数据与配套数据集：《体相磁特性源于微米级超颗粒相互作用且可在纳米尺度调控》。 磁超颗粒（magnetic supraparticles，SPs）可作为微米级颗粒添加剂掺入各类基体材料中，用作身份标识标签或环境触发事件记录器。结合磁颗粒光谱法（magnetic particle spectroscopy，MPS）——该技术可在室温环境下于数秒内完成磁信息读取——磁超颗粒成为一种为材料赋予信息存储功能的高效方案。其所编码的信息依赖于选定纳米颗粒在超颗粒内部的磁相互作用（intra-SP interactions）。然而，此前研究尚未考虑超颗粒间可能存在的磁相互作用（inter-SP interactions）——这类相互作用同样会改变磁颗粒光谱法的检测信号。本文阐明：显著的超颗粒间相互作用确实存在，且可通过调控超颗粒结构实现定制化调控，具体可通过精准调整其超颗粒内相互作用完成，这一结论已通过3D-MuMax模拟与粘性流体中的实验得到验证。具有强超颗粒间相互作用的超顺磁性氧化铁纳米颗粒（superparamagnetic iron oxide nanoparticle）基超颗粒粉体，其磁颗粒光谱法检测信号与掺入基体后的状态相比存在显著差异。而通过掺入非磁性SiO₂纳米颗粒以获得弱超颗粒间相互作用的超颗粒粉体，在掺入基体前后的检测信号几乎无变化。鉴于超颗粒内与超颗粒间相互作用的相互依存特性，这两类极端的超颗粒间相互作用均可适用于多种应用场景，且均可在纳米尺度进行精准调控。