EFFECTS OF ORDERING DOMAIN STRUCTURE ON DIELECTRIC PROPERTIES OF DOUBLE PEROVSKITE La2NiMnO6

Abstract

Two sets of La2NiMnO6 ceramics with different B-site ordering degree were prepared and evaluated. The valence states of Ni2+ and Mn4+ were confirmed, and the B-site ordering degree was estimated qualitatively using magnetic and Raman analysis. The ordering of Ni2+ and Mn4+ was the primary origin for the relaxor-like behavior of the present ceramics. The ordering degree of B-site ions greatly affected the dielectric properties, i.e., more ordered sample indicated higher dielectric constant. Meanwhile, the grain boundary layer capacitor (GBLC) effect was also activated but limited at the high temperatures and low frequencies.