. "Nuzhnyy, Dmitry" . . "[EC6D5CB575FE]" . "7"^^ . . "Buixaderas, Elena" . . "Lattice dynamics and phase transitions in KNbO3 and K0.5Na0.5NbO3 ceramics" . "RIV/68378271:_____/09:00331199!RIV10-AV0-68378271" . "RIV/68378271:_____/09:00331199" . "5"^^ . . . "Berta, Milan" . . . "Gregora, Ivan" . . . . "Mali\u010D, B." . "ferroelectrics; lattice dynamics; phonons Ir and Raman spectroscopy; piezoelectrics; THz spectroscopy"@en . . . "56" . "Kosec, M." . "Lattice dynamics and phase transitions in KNbO3 and K0.5Na0.5NbO3 ceramics"@en . . . "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control" . . "323331" . . "P(GA202/06/0403), P(IAA100100701), P(KAN301370701), Z(AV0Z10100520)" . . . "Kamba, Stanislav" . "Buixaderas, Elena" . "0885-3010" . . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . . . . "Lattice dynamics and phase transitions in KNbO3 and K0.5Na0.5NbO3 ceramics"@en . "Lattice dynamics and phase transitions in KNbO3 and K0.5Na0.5NbO3 ceramics" . . "7"^^ . "Phonons in both ceramic samples KNbO3 (KN) and K0.5Na0.5NbO3 (KNN-50) were investigated from 10 to 900 K by means of Raman, infrared, and THz spectroscopy. First-order transitions from cubic to tetragonal phases were detected at about 755 K (in KN) and 710 K (in KNN-50), where the first component of the polarization appears. Transitions from the tetragonal to the orthorhombic phases take place around 510 and 475 K, respectively. The last transitions from orthorhombic to rhombohedral phases are strongly first-order type. TC is shifted from 200 K in KN to about 90 K in KNN-50. All Raman active modes below 200 cm-1 disappear in KN but not in KNN-50. The overdamped soft mode present at high temperatures in the THz range changes its dielectric strength at each phase transition." . "00026929830001" . "9" . "Phonons in both ceramic samples KNbO3 (KN) and K0.5Na0.5NbO3 (KNN-50) were investigated from 10 to 900 K by means of Raman, infrared, and THz spectroscopy. First-order transitions from cubic to tetragonal phases were detected at about 755 K (in KN) and 710 K (in KNN-50), where the first component of the polarization appears. Transitions from the tetragonal to the orthorhombic phases take place around 510 and 475 K, respectively. The last transitions from orthorhombic to rhombohedral phases are strongly first-order type. TC is shifted from 200 K in KN to about 90 K in KNN-50. All Raman active modes below 200 cm-1 disappear in KN but not in KNN-50. The overdamped soft mode present at high temperatures in the THz range changes its dielectric strength at each phase transition."@en .