Dielectric relaxation, electrical conductivity and optical studies of solid-state synthesized EuCrO3

Structural, morphological, dielectric and optical properties of double perovskites RBaFeTiO6 (R = La, Eu)

“…Indeed, the optical band gap ( E g ) is determined by using Tauc relation: 40 αhυ = A ( hυ − E g ) n where α is the absorption coefficient, ( hυ ) is the incident photon energy, A is the characteristic parameter, while n is an exponent that is related to the optical absorption process and equal to 1/2 for a direct allowed transition or 2 for an indirect allowed transition. 41 Fig. 7(b and c) representing the Tauc plots revealed a direct band gap with an energy of 3.75 eV and 3.53 eV for the LaBaFeTiO 6 and EuBaFeTiO 6 , respectively.…”

“…Such behavior is termed as dielectric relaxation explained on the basis of dominant polarization mechanisms changing gradually with frequency due to the difference in their characteristic times. 41,44 At low frequencies, all polarization mechanisms contribute to the dielectric constant. With the frequency rise, the contributions of these various types of polarizations decrease progressively and hence the dielectric constant decreases along with frequency.…”

Photocatalytic Degradation of Methylene Blue from Aqueous Medium onto Perlite-Based Geopolymer

“…e absorbance spectrum of the asprepared sample is depicted in Figure 4. e optical band gap energy (E g ) was estimated based on absorbance data, as proposed by Wood and Tauc [25,26]. According to Tauc equation, the optical absorption coefficient (α) is related to the energy band gap by…”

Synthesis and Optical Properties of Potassium‐Based Wide‐Bandgap Mixed–Halide Perovskite KPbF2Cl Nanorods

“…To determine the bandgap (E g ) of the system, a Tauc plot (Figure 7) is made by using αhγ = A(hγ À E g ) n , where α is the absorption coefficient, h is the Planck's constant, γ is the frequency of the incident photons, A is an energyindependent proportionality constant, and the exponent n denotes the type of electronic transition between the conduction and valence bands, such as n = 1/2, 2, 3, and 3/2 for direct allowed, indirect allowed, indirect forbidden, and direct forbidden transition, respectively. [38][39][40][41] Since an indirect bandgap is found in KPbF 2 Cl from our calculations, here n = 2 is considered for the Tauc plot (see inset of Figure 7). The intercept of the line along the slope on the hγ axis represents E g with (αhγ) 1/2 equal to zero, providing a bandgap of 4.04 eV.…”