Giant Dielectric Permittivity of Electron-Doped Manganite Thin Films, Ca(1-x)La(x)MnO(3) ($0<= x<= 0.03)

TL;DR

This study reports a giant dielectric constant in electron-doped manganite thin films, attributed to an internal barrier-layer capacitor structure, with values surpassing those of traditional IBLC materials across a broad temperature range.

Contribution

It demonstrates a new material system with exceptionally high dielectric permittivity due to internal barrier-layer effects, expanding the understanding of dielectric properties in doped manganites.

Findings

Dielectric constant ~10^6 observed over 4K to 300K.

Room-temperature dielectric constant increases with La doping.

Values exceed those of conventional IBLC materials.

Abstract

A giant low-frequency, in-plane dielectric constant, eps~10^6, for epitaxial thin films of Ca(1-x)La(x)MnO(3) (x<=0.03) was observed over a broad temperature range, 4K <= T 300K. This phenomenon is attributed to an internal barrier-layer capacitor (IBLC) structure, with insulating boundaries between semiconducting grains. The room-temperature eps increases substantially with electron (La) doping. The measured values of eps exceed those of conventional two-phase IBLC materials based on (Ba,Sr)TiO(3) as well as recently discovered CaCu(3)Ti(4)O(12) and (Li,Ti) doped NiO.