Exploring Exchange Bias Coupling in Fe3−δO4@CoO Core–Shell Nanoparticle 2D Assemblies
Exploring Exchange Bias Coupling in Fe3−δO4@CoO Core–Shell Nanoparticle 2D Assemblies
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DOI：
10.1002/adfm.201706957
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发表时间：
2018-06
影响因子：
19
通讯作者：
Mathias Dolci;Yu Liu;Xiaojie Liu;C. Leuvrey;A. Derory;D. Bégin;S. Bégin-Colin;B. Pichon
中科院分区：
文献类型：
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作者：
Mathias Dolci;Yu Liu;Xiaojie Liu;C. Leuvrey;A. Derory;D. Bégin;S. Bégin-Colin;B. Pichon
表现出交换偏置耦合的核壳铁磁性@反铁磁性（F（i）M@AFM）纳米颗粒非常有希望推回超顺磁性极限。然而，它们的内禀磁性会受到粒子间相互作用的强烈影响。这项工作报告了Fe 3-dO4@CoO核壳纳米颗粒的集体性质，作为其组装结构的函数。纳米颗粒组装体的结构由位于基底和纳米颗粒表面的互补官能团之间的铜（I）催化的炔-叠氮化物环加成（CuAAC）“点击”反应控制。制备了具有可调尺寸的纳米颗粒的2D阵列，其尺寸范围从少数纳米颗粒的簇到致密且均匀的单层。纳米颗粒的空间排列强烈影响交换偏置耦合，这对于大的2D纳米颗粒组装体是显著增强的，并且在3D组装体（诸如粉末）中甚至更多，这有利于弱的和随机的偶极相互作用。
Core‐shell ferro(i)magnetic@antiferromagnetic (F(i)M@AFM) nanoparticles exhibiting exchange bias coupling are very promising to push back the superparamagnetic limits. However, their intrinsic magnetic properties can be strongly affected by interparticle interactions. This work reports on the collective properties of Fe3–dO4@CoO core‐shell nanoparticles as function of the structure of their assembly. The structure of nanoparticle assembly is controlled by a copper (I) catalyzed alkyne–azide cycloaddition (CuAAC) “click” reaction between complementary functional groups located at the surface of both substrates and nanoparticles. 2D arrays of nanoparticles with tunable sizes ranging from clusters of few nanoparticles to a dense and homogenous monolayer were prepared. The spatial arrangement of nanoparticles strongly influences the exchange bias coupling which is significantly enhanced for large 2D nanoparticle assemblies and, even more in 3D assemblies such as powder, which favour weak and random dipolar interactions.