Open AccessPhonon anomaly in Sm2BaNiO5
Author(s) -
С. А. Климин,
E. A. Popova,
М. Н. Попова
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1389/1/012039
Subject(s) - phonon , anomaly (physics) , condensed matter physics , dielectric , magnetic field , physics , ion , magnetic anomaly , order (exchange) , materials science , quantum mechanics , geophysics , finance , economics
We present low-temperature far-infrared study of Sm 2 BaNiO 5 . The lowest-frequency phonon of Sm 2 BaNiO 5 generated by the motion of the Sm 3+ ion demonstrates anomalous behaviour at temperatures lower than the Néel temperature, T < T N =55 K. This phonon hardens at the magnetic ordering although its frequency shift does not follow the magnetic order parameter. The observed phenomenon is responsible for an unusual dielectric response of Sm 2 BaNiO 5 reported in the literature. A correlation between the temperature behaviour of crystal-field levels and the phonon anomaly is discussed.