The invention provides a high-
emissivity and high-entropy
ceramic material and a preparation method and application thereof, and belongs to the technical field of high-entropy
ceramic materials. Five
rare earth elements with different
doping proportions are simultaneously introduced into the
crystal lattice position of La, the number of
impurity energy levels between the
valence band top and the
conduction band bottom of LaMgAl11O19 is increased, the forbidden
band width is reduced, electrons in the
impurity energy levels can absorb energy of
infrared light to jump to the
conduction band, and then the spectral
emissivity of the corresponding
wave band is improved; according to the invention, Pr, Ce or Eu elements with variable valence are introduced into the LaMgAl11O19
ceramic material, and when the valence state of the Pr, Ce or Eu elements is changed, the concentration of free electrons in a
system can be increased (for example, the valence of Pr < 3 + > is changed to Pr < 4 + >) so that the absorption of free carriers to
infrared light is promoted, and the improvement of spectral
emissivity is also facilitated. The spectral emissivity of the ceramic material in the
infrared band of 3-5 [mu] m is greater than 0.85, and the ceramic material has a good application prospect.