Effect of progressive substitution of Lu by Ho on the structural and dielectric properties of nanocrystalline LuFeO3 orthoferrite

High Energy Density Achieved in Novel Lead-Free BiFeO3–CaTiO3 Ferroelectric Ceramics for High-Temperature Energy Storage Applications

“…The real (ε′) and imaginary (ε″) parts, of the complex dielectric permittivity ε* = ε′ – iε″, have been recorded in the frequency range of 16 kHz ≤ f ≤ 3 GHz to study the dielectric relaxation behavior − of (1 – x )BFO- x CTO ceramics, as shown in Figures d–f (16 kHz ≤ f ≤ 20 MHz) for x = 0.6, 0.7, and 0.8 respectively. The dielectric relaxation time is calculated using Cole–Cole distribution functions, which are derived from a modified Debye equation as follows: ε * = ε ′ − i ε ′′ = ε ∞ + ε 0 − ε ∞ 1 + false( normali ω τ false) 1 − α Here ω is 2π f , τ is the mean dielectric relaxation time, ε 0 (static permittivity ω → 0) is the permittivity at extremely low frequency, and ε ∞ is defined as the permittivity at high frequency.…”