Dielectric properties of (Y0.2Eu0.2Er0.2Dy0.2Lu0.2)3(AlxFe1-x)5O12 high-entropy garnet ceramics

A new kind of novel high-entropy rare earth garnet ceramics (HEREGCs, (Y 0.2 Eu 0.2 Er 0.2 Dy 0.2 Lu 0.2 ) 3 (Al x Fe 1-x ) 5 O 12 (x = 0.4–0.6)) was designed and successfully synthesized by solid state reaction method. With the increase of Al content, the relative dielectric constant (ε r ′) at 100 Hz decreases from 4×104 to 1×102, while the dielectric loss (tanδ) increases from 0.93 to 2.65. The activation energy of grain boundary electrical conductivity (E gb ) and grain electrical conductivity (E g ) are fitted according to Arrhenius’ law, which indicate that the increase of difference between E gb and E g lead to the enhancement of dielectric properties. Our results provide the underlying insights needed to guide the study of colossal dielectric materials.