Gamma-radiolytic preparation of multi-component oxides

• Precursors to Zn1−xCdxO and (Lu,Y)3Al5O12 oxides were formed under γ-radiation.
• Heat treatment was required for wurtzite (ZnO) or garnet (YAG) modification forming.
• Phase-pure Zn0.97Cd0.03O solid solution with the maximum Cd content was prepared.
• Phase-pure (Lu,Y)3Al5O12:Ce garnets up to 2 M% of Ce were produced.
• Crystallite size amounts 50 nm for Zn1−xCdxO and 100 nm for (Lu,Y)3Al5O12.

The preparation of solid precursors to Zn1−xCdxO and (Lu,Y)3Al5O12:Ce induced by 60Co gamma-ray irradiation of aqueous solutions containing soluble metal salts and ammonium formate is presented. Due to the irradiation, crystalline zinc carbonate hydroxide Zn4(CO3)(OH)6·H2O or amorphous carbonates of Lu, Y and Al were formed in the solutions. After calcination at 500 °C, the agglomerated phase-pure Zn1−xCdxO with crystallite size about 50 nm was obtained if the Cd concentration in solutions remained below 16 M% (with respect to Zn) with x being up to 0.035. The solid precursors to garnets contained the intended concentration of all elements, according to X-ray fluorescence analysis. After calcination at 1200 °C in mild vacuum, the respective phase-pure garnets with crystallite size 100 nm or their solid solution were produced when the Ce dopation was kept below 2 M% (with respect to rare-earth metals). The Ce solubility in the garnet lattice was estimated as 1–2 M% at the calcination conditions used.