Methods for making an environmental barrier coating using a sintering aid involving: applying a bond coat layer to the ceramic component; combining at least water and a primary transition material selected from a rare earth disilicate or a doped rare earth disilicate to produce a transition layer slurry; applying the transition layer slurry to the bond coat layer; infiltrating a sol-gel solution comprising at least one sintering aid into the applied slurry; and sintering the component to produce the environmental barrier coating having at least the bond coat layer and a transition layer formed from the transition layer slurry during sintering. During sintering the sintering aid dopes the primary transition material with at least one doping composition.