How do I make a dysprosium chloride solution from dysprosium oxide?
DyCl3 is often prepared by the "ammonium chloride route," starting from either Dy2O3 or hydrated chloride or oxychloride.[2][3] or DyCl3·6H2O.[4] These methods produce (NH4)2[DyCl5]:

    10 NH4Cl + Dy2O3 → 2 (NH4)2[DyCl5] + 6 NH3 + 3 H2O

    DyCl3·6H2O + 2 NH4Cl → (NH4)2[DyCl5] + 6 H2O


The pentachloride decomposes thermally according to the following equation:

    (NH4)2[DyCl5] → 2 NH4Cl + DyCl3


The thermolysis reaction proceeds via the intermediacy of (NH4)[Dy2Cl7].

Treating Dy2O3 with aqueous HCl produces hydrated chloride (DyCl3·6H2O). This salt cannot be rendered anhydrous by heating. Instead one obtains an oxychloride.

source: wikipedia