Dielectric Properties of Rare Earth Substituted Cu–Zn Ferrites

Abstract

Samples with the chemical formula Cu0.5Zn0.5Fe2−xRxO4 (R = La, Nd, Sm and Gd; x = 0 and 0.1) were prepared by the standard ceramic method. The real part of the dielectric constant ε′ and the ac electrical conductivity σac are measured and the dielectric loss tangent tan δ is calculated in the frequency range 50–105 Hz and from room temperature up to ≅800 K. ε′ and tan δ are found to decrease with increasing the frequency while σac is generally increased. On the contrary ε′, σac and tan δ are increased with temperature. No relaxation was detected in tan δ(f) in the investigated frequency range while tan δ(T) showed two maxima. The composition dependence of the dielectric parameters is discussed and the results are explained using Koops's model. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Influence of composition on structure, morphology and dielectric properties of BixAlyOz composite films synthesized by atomic layer deposition

“…29 Due to this conductivity, relaxation has deviated from the ideal Debye process, resulting in the broadening and deformation of the loss peaks. 30 We can see, however, that the loss peaks of all the samples appear at lower frequencies than the Z and M peaks, which can be ascribed to the influence of the relaxation ratio r=ε s /ε ∞ . 31 Although there is an inconsistent peak position of tan δ and Z /M , as reported, the peak position of M is more appropriate for evaluating the relaxation time distribution.…”

Frequency and Voltage-Dependent Dielectric Properties and AC Electrical Conductivity of (Au/Ti)/Al2O3/n-GaAs with Thin Al2O3Interfacial Layer at Room Temperature

“…3a, ε exhibits much the same value in the inversion region, for each frequency. Such behavior of C and G/ω or ε and ε is known as inductive behavior, due to the effect of R s and surface states [22,23]. The tan δ versus V plot for each frequency also exhibits U-shape behavior like the ε versus V plot, due to inductive behavior of the structure.…”

Investigation of negative dielectric constant in Au/1 % graphene (GP) doped-Ca1.9Pr0.1Co4Ox/n-Si structures at forward biases using impedance spectroscopy analysis

“…In addition, the increase in r ac with increasing frequency leads to an increase in the eddy current, which in turn increases in the tan d. Especially, at high voltages, the dispersion in r ac trend can be attributed to the conducting nature of charge carriers and surface states. Usually, the frequency response of the dielectric properties and electric modulus are dominated by a low frequency dispersion but its physical origin has long been in question [44][45][46][47].…”