Layered double hydroxides (LDH), also known as anion-exchange clays, represent a numerous family of promising two-dimensional materials with the general formula [M2+1-xM3+x(OH)2]x+(Ay-)x/y·zH2O. LDH are composed of alternating positively charged mixed metal M2+-M3+ hydroxide layers, in which the oxygen octahedral MO6 are edge-linked, and interlayers occupied by anions (Ay-) and water molecules. Since the magnetic properties of such LDH are dependent on the cation content and the interlayer distance, they can be used in the development of hybrid magnets and related materials.
In our work, the precipitation of nanocrystallites of cobalt–aluminium LDH in a magnetic field has been studied. In a magnetic field perpendicular to the substrate, dense and homogeneous films have been obtained. We have proposed a theoretical model that predicts the magnetic anisotropy of the crystallites, explained by the specific preferential distribution of cobalt ions in honeycomb-like lattice in LDH layers. The well-ordered films obtained by the preparation in the magnetic field perpendicular to the substrate display a magnetic anisotropy.
The results of our study were published in the prestigious journal Chemical Communications [D.E.L. Vieira et al., Chem. Commn. 57 (2021) 6899-6902] with impact factor of 6.222, which is included in Nature index.