Effect of carbonate precursor synthesis conditions on the formation of monodisperse Nd:YAG nanopowders

Abstract

Using electroacoustic spectroscopy and X-ray diffraction, we have studied the formation of monodisperse Y3Al5O12:Nd3+ doped garnet nanopowders (1 at % Nd) from carbonate precursors in the form of a system of two basic carbonates, Y(OH)CO3 · nH2O and NH4Al(OH)2CO3, in amorphous and crystalline states. The results demonstrate that monodisperse YAG nanopowders can be obtained from weakly agglomerated carbonate precursors with a nearly unimodal size distribution of particle conglomerates, produced by chemical precipitation from a dilute (0.15 M Al3+) aqueous chloride solution with ammonium bicarbonate and subsequent aging of the precipitate at room temperature and pH 7.86–7.89. The zeta potential of the disperse system for the carbonate precipitate suspension in its dynamic equilibrium is 4.3 ± 0.5 mV at an average nanoparticle conglomerate size of 165 ± 5 nm. After heat treatment of the carbonate precursors at temperatures from 1100 to 1200°C, we obtained single-phase Nd:YAG doped garnet nanopowders. The cubic cell parameter a of the Nd:YAG varies from 1.2022 to 1.2025 nm, depending on the synthesis temperature, and its crystallite size varies from 35 to 50 nm.