Franck−Condon Modes in Sr₂MnWO₆ Double Perovskite

Temperature evolution of the band gap inBiFeO3traced by resonant Raman scattering

“…Other possible phenonema are more difficult to reconcile with the experimental observations. Notably, the Franck-condon mechanism explaining the resonance behavior reported in past studies [25,27] does not have the same signature, both at ambient condition (e.g. no 3 rd -order scattering is observed in our studies) and as a function of temperature.…”

“…In this letter, we make use of resonant Raman scattering, which occurs when the incident or scattered photon energy is close to an electronic transition. These resonant effects have been investigated in many details in semiconductors [18][19][20][21] but have been much less investigated in ferroic perovskites; they have been used either as a probe for the structural behavior [22][23][24] or electronic transitions involving mostly charge transfer phenomena [25][26][27][28] that are difficult to transfer to the case of pure BiFeO 3 .…”

Modifying La0.6Sr0.4MnO3 Perovskites with Cr Incorporation for Fast Isothermal CO2‐Splitting Kinetics in Solar‐Driven Thermochemical Cycles

“…partial substitution of Cr 3+ by Cr 4+ (r + Cr 4 = 0.55 Å, r + Cr 3 = 0.615 Å in sixfold coordination). The strong mode around 720 cm −1 is in accordance with previously reported Raman spectra of La 1−y Sr y Cr 0.1 Mn 0.9 O 3 [44] and could be ascribed according to structurally related perovskite solid solutions [45][46][47][48][49][50][51] to an A g -like local oxygen breathing mode. [41] To probe this hypothesis, we turn to Raman spectroscopy analyzing the near order structural characteristics of the perovskite solid solutions (Figure 3b).…”

“…2019, 9,1803886 10 mol% Cr, x = 0.1, a new band around 715 cm −1 emerges, which grows and shifts to lower wavenumbers when increasing the Cr content ( Figure 3c). The strong mode around 720 cm −1 is in accordance with previously reported Raman spectra of La 1−y Sr y Cr 0.1 Mn 0.9 O 3 [44] and could be ascribed according to structurally related perovskite solid solutions [45][46][47][48][49][50][51] to an A g -like local oxygen breathing mode. Cr 4+ causes a Jahn-Teller distortion of the (Cr 4+ )-O 6 octahedron, which can create the local lattice distortion activating the 720 cm −1 mode, see ref.…”

Crystal growth and magnetic properties of the double perovskites R2MnNiO6 (R=Pr, Sm and Ho) by a hydrothermal route

“…Double perovskite oxides with a general formula A 2 BB 0 O 6 or AA 0 BB 0 O 6 (where A and A 0 are alkaline-earth and/or rare-earth metals and B and B 0 are transition metals) have been extensively investigated for their superconductivity [1], magnetic [2,3], dielectric properties [4] and colossal magnetoresistance (CMR) [5,6]. As a special group of double perovskite oxides, A 2 MnNiO 6 (A¼rare earth, Y and Bi) have attracted considerable attention since a near-roomtemperature ferromagnetic transition (T C ¼280 K) was observed in La 2 MnNiO 6 [7][8][9].…”