Study of the behaviour of the dielectric constant in Cu,Fe:BaTiO3

Dielectric Properties in Transition Metal and Rare‐Earth‐Doped Multiferroic BaTiO3 Nanoparticles

“…It can be seen that a high concentration of Fe-doping decreases the dielectric function ϵ 0 of BTO NPs. The peak of ϵ 0 is smaller and shifts to smaller phase transition temperature T C values with increasing Fe concentration x, in qualitative agreement with the experimental data of Costanzo et al, [3] Mishra and Mishra, [34] and Ouedraogo et al [35] It must be noted that the Fe-doping concentration used by these authors is smaller (x ¼ 0-4%, 1.5%, and 1.4%, respectively) than ours. But the behavior of ϵðT, xÞ is the same.…”

“…It must be mentioned that there are also compounds where the peak value of the DC ϵ 0 increases, but the ferroelectric transition temperature T C decreases (e.g., by Cu or Sm doping [35,65,66] ) or vice versa-ϵ 0 decreases, whereas T C increases (e.g., by Nb doping [67] ). May be there is a combination, a competition between tensile and compressive strains.…”

Ferroelectric Phase Transition in Cu-doped BaTiO3 Crystals

“…3). A broadening and flattening of the maximum of ε(T) and a shift of the Curie temperature T c have also been observed in Fe-doped BaTiO 3 ceramics [10,11]. Similar effects also exist in the potassium tantalite niobate [12] and in several oxides with perovskite structure: Nb:KTaO 3 , Cu,La:PbTiO 3 [13].…”

“…Oxygen vacancies are created by heating, the gap is reduced as a result, and the Curie temperature increases T c [1]. From ε -1 (T), Ouedraogo et al [11] determined the Curie constants as 13×10 4 K in ferroelectric phase and 25×10 4 K in paraelectric phase (i.e., a ratio of 2 for 1.6% Fe:BaTiO 3 ). These values are not affected when the samples are subjected to a laser irradiation (λ=5145Ǻ).…”