Počet záznamů: 1
THz and infrared studies of multiferroic hexagonal Y.sub.1-x./sub.Eu.sub.x./sub.MnO.sub.3./sub. (x = 0 - 0.2) ceramics
0353097 - FZU-D 2011 RIV GB eng J - Článek v odborném periodiku
Goian, Veronica - Kamba, Stanislav - Kadlec, Christelle - Nuzhnyy, Dmitry - Kužel, Petr - Moreira, J.A. - Almeida, A. - Tavares, P.B.
THz and infrared studies of multiferroic hexagonal Y1-xEuxMnO3 (x = 0 - 0.2) ceramics.
Phase Transitions. Roč. 83, 10-11 (2010), s. 931-941 ISSN 0141-1594
Grant CEP: GA ČR(CZ) GA202/09/0682
Výzkumný záměr: CEZ:AV0Z10100520
Klíčová slova: multiferroics * infrared and THz spectroscopy * phonons
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 1.006, rok: 2010
We report an investigation of hexagonal Y1-xEuxMnO3 ceramics with x=0, 0.1 and 0.2 using infrared and THz spectroscopies in the temperature range between 5 and 900 K. The temperature dependence of the THz permittivity reveals a kink near the antiferromagnetic phase transition temperature TN 70 K giving evidence of a strong spin-lattice coupling. Below TN two absorption peaks were revealed in the THz spectra close to 43 and 73 cm-1. While the first peak corresponds to a sharp antiferromagnetic resonance exhibiting softening on heating towards TN, the second one may be attributed to an impurity mode or a multiphonon absorption peak. High-temperature THz spectra measured up to 900 K reveal only small gradual increase of the permittivity in agreement with a weak phonon softening observed in the infrared reflectance spectra upon heating. This corresponds to an improper ferroelectric character of the phase transition proposed from first principle calculations by Fennie and Rabe.
Trvalý link: http://hdl.handle.net/11104/0192437