Rare Earth Oxide Synthesis Using Cy923

Cy923, composed by 4 trialkyl
phosphine oxides including, dioctylhexyl-phosphine oxide (37.4%),
octyldihexyl-phosphine oxide (30.4%), trioctyl-phosphine oxide (16%),
and dihexyl-phosphine oxide (8.5%)^{28 (link)} (purity:
93%, density: 880 kg/m³, molecular weight: 348 g/mol, Cytec
Industries Inc., Canada); chitosan (medium molecular weight, acetylation
degree: 0.23, batch number: BCCD5444, Sigma-Aldrich); glacial acetic
acid (CH₃COOH, 100%, Sigma-Aldrich); yttrium oxide (Y₂O₃, 99%, Alfa Aesar); gadolinium oxide (Gd₂O₃, 99%, Alfa Aesar); lanthanum oxide (La₂O₃, 99%, Alfa Aesar); nitric acid (HNO₃, 65%,
Alfa Aesar); and ammonium nitrate (NH₄NO₃, 98%,
Fluka, Switzerland) were used.