Effect of alkali metal (Na, K) ion ratio on structural, optical and photoluminescence properties of K0.5Na0.5NbO3 ceramics prepared by sol–gel technique

Polarized Raman, infrared and dielectric spectra of lead-free K0.5Na0.5NbO3 piezoelectric system: insights from ab-initio theoretical and experimental studies

“…The room temperature Raman spectra of the sintered KNN sample in the wavenumber range of 100-1000 cm −1 is displayed in figures 4 and 7(a). The observed Raman spectrum is consistent with previous reports [23][24][25][26][27]. It is evident from the figure 7(a) that the KNN spectra consist of three characteristic Raman peaks (259, 609, 852 cm −1 ) that are associated with the internal vibrations of the NbO 6 octahedron.…”

“…(cm −1 ) Raman Int. This work Reference [23] Reference [24] Reference [25] Reference [26] 4) and with those reported earlier [23][24][25][26][27]. The figure 4 shows the computed average Raman intensity spectrum which is in good agreement with experimental spectrum (See figures 4 and 7(a)).…”

“…Further, no theoretical studies that can support the experimentally measured Raman spectra, optical spectra, dielectric properties of KNN etc have been reported. Over the years, the Raman and Infrared (IR) spectra have been used to explore different structural aspects of various material systems including KNN based piezoceramics [23][24][25][26][27]. The importance of these techniques stems from their ability to provide precise information of ionic configurations and local distortions in the crystal structure [28][29][30].…”