Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
Inorg Chem. 2011 May 16;50(10):4295-300. doi: 10.1021/ic1022054. Epub 2011 Apr 20.
Core/shell and core/shell/shell particles comprised of the Prussian blue analogues K(j)Ni(k)Cr(CN)(6)·nH(2)O (A) and Rb(a)Co(b)Fe(CN)(6)·mH(2)O (B) have been prepared for the purpose of studying persistent photoinduced magnetization in the heterostructures. Synthetic procedures have been refined to allow controlled growth of relatively thick (50-100 nm) consecutive layers of the Prussian blue analogues while minimizing the mixing of materials at the interfaces. Through changes in the order in which the two components are added, particles with AB, ABA, BA, and BAB sequences have been prepared. The two Prussian blue analogues were chosen because B is photoswitchable, and A is ferromagnetic with a relatively high magnetic ordering temperature, ~70 K, although it is not known to exhibit photoinduced changes in its magnetic properties. Magnetization measurements on the heterostructured particles performed prior to irradiation show behavior characteristic of the individual components. On the other hand, after irradiation with visible light, the heterostructures undergo persistent photoinduced changes in magnetization associated with both the B and A analogues. The results suggest that structural changes in the photoactive B component distort the normally photoinactive A component, leading to a change in its magnetization.
为了研究异质结构中持久的光致磁化，制备了由普鲁士蓝类似物 K(j)Ni(k)Cr(CN)(6)·nH(2)O (A) 和 Rb(a)Co(b)Fe(CN)(6)·mH(2)O (B) 组成的核/壳和核/壳/壳颗粒。合成过程得到了改进，允许在最小化界面处材料混合的情况下，控制相对较厚（50-100nm）的普鲁士蓝类似物连续层的生长。通过改变两种成分的添加顺序，可以制备出 AB、ABA、BA 和 BAB 序列的颗粒。选择这两种普鲁士蓝类似物是因为 B 是光可切换的，而 A 是具有相对较高的磁有序温度（~70K）的铁磁体，尽管它是否表现出其磁性质的光致变化尚不清楚。在辐照前对异质结构颗粒进行的磁化测量显示出与各个成分特征一致的行为。另一方面，在可见光辐照后，异质结构经历了与 B 和 A 类似物都相关的持久的光致磁化变化。结果表明，光活性 B 成分的结构变化使通常光非活性的 A 成分变形，导致其磁化发生变化。
