Abstract: A heat-insulating layer has a melting point above 2500° C., a thermal expansion coefficient in excess of 8×10?6 K?1, and a sintering temperature greater than 1400° C. This material has a perovskite structure of the general formula A1+r(B?1/2+xB?1/2+y)O3+z in which: A=at least one element of the group (Ba, Sr, Ca, Be), B?=at least one element of the group (Al, La, Nd, Gd, Er, Lu, Dy, Tb), B?=at least one element of the group (Ta, Nb), and 0.1<r,x,y,z<0.1.

Abstract: A heat-insulating material has a melting point above 2500° C., a thermal expansion coefficient in excess of 8×10?6 K?1, and a sintering temperature greater than 1400° C. It has a perovskite structure of the general formula A1+r(B?1/3+xB?2/3+y)O3+z where A=at least one element of the group (Ba, Sr, Ca, Be), B?=at least one element of the group (Mg, Ca, Sr, Ba, Be), B?=at least one element of the group (Ta, Nb), r, x, and z?0, and ?0.1<r, x, y, z<0.1; or of the general formula A1+r(B?1/2+xB?1/2+y)O3+z where A and B? are as above and B?=at least one element of the group (Al, La, Nd, Gd, Er, Lu, Dy, Tb), and ?1.0<r, x, y, z<0.1.