1 research outputs found
Minerals to Materials: Bulk Synthesis of Aqueous Aluminum Clusters and Their Use as Precursors for Metal Oxide Thin Films
We
describe a process to produce aqueous precursor solutions of
the <i><b>flat</b></i><b>-Al</b><sub><b>13</b></sub> hydroxo cluster (Al<sub>13</sub>(μ<sub>3</sub>-OH)<sub>6</sub>(μ<sub>2</sub>-OH)<sub>18</sub>(H<sub>2</sub>O)<sub>24</sub>(NO<sub>3</sub>)<sub>15</sub>) via stoichiometric dissolution
of bulk AlÂ(OH)<sub>3</sub>(s) in HNO<sub>3</sub>(aq). We highlight
its facility by demonstrating high yields and large-scale synthesis.
X-ray diffraction confirms formation of a single-phase product, and
Raman spectra show characteristic O-Al-O vibrational modes, both techniques
confirming the identity of the <i><b>flat</b></i><b>-Al</b><sub><b>13</b></sub> cluster in the bulk. <sup>27</sup>Al NMR spectroscopy and dynamic light scattering also confirm the
presence of the cluster in aqueous solution. We show the as-prepared
solution produces smooth and continuous thin films via spin-coating.
In capacitors, the films exhibit low leakage currents (near 10 nA/cm<sup>2</sup>) and dielectric constants expected for amorphous Al<sub>2</sub>O<sub>3</sub>. Because the precursor preparation requires no postsynthesis
purification, it is readily scalable to large volumes