Patent ID: 8858822

Claim:
A material comprising: a ceramic material having the empirical formula A′ 1−b−c B′ b C′ c where: 0<b≦0.5 and 0<c≦0.01; wherein A′ represents the composition Pb(Zr a Ti 1−a )O 3 and 0.5≦a≦0.6 and A′ serves as host lattice for B′ and C′, B′ is an additive component of the perovskite lattice type and is selected from the following components: KNbO 3 , Pb(M II 1/2 M VI 1/2 )O 3 ) where M II is Zn, Co, Ni, Mn or Cu and where M VI is W, Pb(M III 1/2 M V 1/2 )O 3 where M III is Fe, Mn, Cr, or Ga and M V is Nb, Ta, or Sb, Pb(M III 1/2 M VI 1/3 )O 3 where M III is Fe, Mn, Cr, or Ga and M VI is W, Pb(Li I 1/4 M V 3/4 )O 3 where M V is Nb, Ta or Sb, C′ is a ceramic material of the cryolite lattice type which has the general formula A 4 (B 2−2x/3 Nb 2+2x/3 )O 11+x V 1−x , where A comprises barium or strontium, where B comprises strontium, magnesium, or calcium, where V comprises an oxygen vacancy having a phase range and the parameter x is such that: 0≦x<1.