. . "Buixaderas, Elena" . "1" . . . . "391" . . . "Polar modes in K0.5Na0.5NbO3 ceramics" . "Kosec, M." . . "Polar modes in K0.5Na0.5NbO3 ceramics"@en . "0015-0193" . "Polar modes in K0.5Na0.5NbO3 ceramics" . . "Buixaderas, Elena" . . . "4"^^ . "Kamba, Stanislav" . "ferroelectrics; lattice dynamics; phonons; Ir and Raman spectroscopy; piezoelectrics; THz spectroscopy"@en . "Nuzhnyy, Dmitry" . . "Gregora, Ivan" . . "Ferroelectrics" . "Polar modes in K0.5Na0.5NbO3 ceramics"@en . "RIV/68378271:_____/09:00331750" . . . "Phonons in K0.5Na0.5NbO3 (KNN-50) ceramics were investigated from 10 to 900 K by means of Raman, infrared and THz spectroscopy. A first-order phase transition was detected from cubic to tetragonal phases at about 710 K, when the first component of the polarization appears. Transition from the tetragonal to the orthorhombic phase takes place around 475 K. The last transition from orthorhombic to rhombohedral phases is strongly first order. Tc is about 90 K and all Raman active modes below 100 cm-1 disappear. An overdamped soft mode is present at high temperatures in the THz range but another excitation below phonons is needed to explain the static value of the permittivity." . "6"^^ . . "P(GA202/06/0411), P(IAA100100701), P(KAN301370701), Z(AV0Z10100520)" . "7"^^ . . . "334027" . "RIV/68378271:_____/09:00331750!RIV10-AV0-68378271" . "Phonons in K0.5Na0.5NbO3 (KNN-50) ceramics were investigated from 10 to 900 K by means of Raman, infrared and THz spectroscopy. A first-order phase transition was detected from cubic to tetragonal phases at about 710 K, when the first component of the polarization appears. Transition from the tetragonal to the orthorhombic phase takes place around 475 K. The last transition from orthorhombic to rhombohedral phases is strongly first order. Tc is about 90 K and all Raman active modes below 100 cm-1 disappear. An overdamped soft mode is present at high temperatures in the THz range but another excitation below phonons is needed to explain the static value of the permittivity."@en . . "[B9605E6C8E30]" . "Mali\u010D, B." . . "GB - Spojen\u00E9 kr\u00E1lovstv\u00ED Velk\u00E9 Brit\u00E1nie a Severn\u00EDho Irska" . . . . "000272607100008" . .