Giant dielectric response in two-dimensional charge-ordered nickelate ceramics

Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People’s Republic of China
Journal of Applied Physics (Impact Factor: 2.19). 10/2008; DOI: 10.1063/1.2969946
Source: IEEE Xplore

ABSTRACT Dielectric relaxations of charge-ordered Ln 1.5 Sr 0.5 NiO 4 ( Ln = La and Nd) ceramics were investigated over a broad temperature range. The giant dielectric constant (over 70 000 ) with a low dielectric loss of ∼0.1 was determined at high frequencies (up to 5 MHz) over a broad temperature range. There are two dielectric relaxations in the vicinity of charge ordering temperatures. The thermal activated small polaronic hopping between two charge ordering temperatures should contribute to the giant dielectric response in the present ceramics. Compared to other giant dielectric constant materials, the present materials have the notable advantage for high frequency applications.

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