Crystals with this property can theoretically experience second sound such as in semi-metal bismuth. These materials are tested by a HIPOT. Hafnium oxide acts as one of these in modern CPUs. The tangent of delta or the dissipation factor describes the energy lost as heat in one of these substances. The macroscopic properties of one of these materials is related to microscopic polarizability by the Clausius-Mossotti relation. This property is quantified by one plus chi over epsilon. A material is one of these if its valence and conduction bands 
Crystals with this property can theoretically experience second sound such as in semi-metal bismuth. These materials are tested by a HIPOT. Hafnium oxide acts as one of these in modern CPUs. The tangent of delta or the dissipation factor describes the energy lost as heat in one of these substances. The macroscopic properties of one of these materials is related to microscopic polarizability by the Clausius-Mossotti relation. This property is quantified by one plus chi over epsilon. A material is one of these if its valence and conduction bands are separated by at least 3 electron volts. At sufficient field strength, these breakdown. They are polarized by an electric field. This sort of material is found between the plates of a capacitor. For 10 points, name this property of a material to act as electric insulators.
Crystals with this property can theoretically experience second sound such as in semi-metal bismuth.
dielectrics [prompt on insulator]