Environmental barrier coating

A method comprising:

• mixing barium-magnesium alumino-silicate particles, SiO2 particles, and silicon oxycarbide particles in a carrier fluid to form a slurry, the barium-magnesium alumino-silicate particles have an average maximum dimension that is between about 10-40% of an average maximum dimension of the silicon oxycarbide particles, and the barium-magnesium alumino-silicate particles are classified and exclude small particles that have a maximum dimension of less than 1 micrometer;
• applying the slurry to a substrate;
• drying the slurry to remove the carrier fluid and thereby form a dried slurry coating;
• curing the dried slurry coating to form a cross-linked green coating;
• and
• sintering the cross-linked green coating to thereby form a barrier layer.