A ceramic composition including a first ceramic material and a second ceramic material that is in the form of nano-, submicron-, or micron-sized particles, in which the first ceramic material has a lower melting point than the second ceramic material, and, when the first ceramic material melts into a liquid and the second ceramic material remains particulate, the second ceramic material floats at the top of the liquid. Also disclosed is a variant of this composition including a first ceramic material and a second ceramic material, in which the second ceramic material has a melting point higher than the first ceramic material, and, when the first ceramic material melts into a liquid, the second ceramic material partially or completely dissolves in the liquid.