Sonia De Almeida-Didry

TL;DR: In this paper, the role of grain boundaries in the colossal permittivity of doped and undoped calcium copper titanate, CaCu3Ti4O12 (CCTO), is illustrated by a first correlation -over four orders of magnitude - between capacitance of CCTO and the capacity of grain boundary, not that of grains, deduced from the analysis of impedance measurements.

TL;DR: In this article, the influence of synthesis methods on the crystalline structure, morphological, optical, magnetic and electrical properties were investigated using X-ray diffraction, RAMAN spectroscopy, scanning electron microscopy, transmission electron microscope, UV-visible diffuse reflectance spectra spectra, superconducting quantum interference device and impedance spectra.

TL;DR: In this paper, core-shell grains of CCTO surrounded by Al2O3 shell were synthesized by ultrasonic sol-gel reaction from alumina alkoxide precursor.

TL;DR: In this paper, it was found that the substitution of Sr 2+ and/or Ni 2+ on Ca and Cu sites respectively increase the grain size of CaCu 3 Ti 4 O 12 ceramics.

TL;DR: In this article, a fit of an RC element model to the impedance spectroscopic data was found to scale with the permittivity measured at 1 kHz weighted by the size of the grains.