| Autor: |
Yen-Chin Huang, Yi-De Liou, Heng-Jui Liu, Hsin-Hua Lee, Yi-Chun Chen, Ying-Hao Chu |
| Jazyk: |
angličtina |
| Rok vydání: |
2017 |
| Předmět: |
|
| Zdroj: |
APL Materials, Vol 5, Iss 8, Pp 086112-086112-7 (2017) |
| Druh dokumentu: |
article |
| ISSN: |
2166-532X |
| DOI: |
10.1063/1.4990138 |
| Popis: |
The rich phase diagram of rhombohedral (R)-like and tetragonal (T)-like monoclinic polymorph in strained BiFeO3 (BFO) films brings on various functionalities. Finding correlations of physical ordering parameters in this system is generally difficult because T-like and R-like phases are undistinguishable in many aspects. In this study, the magnetic-coupled structural transitions of the mixed-phase BFO at low temperatures were investigated by atomic force microscopy (AFM), X-ray diffraction (XRD), and Raman spectroscopy. To resolve the complexity resulted from the similarity between T-like and R-like phases, we analyzed the Raman spectra on a micro-scale region with various T/R ratios, which is in situ manipulated by an AFM tip carrying a dc bias. Phonons of T-like and R-like phases were thus successfully separated. Based on temperature-dependent XRD and resolved Raman spectra, we observed two isostructural transitions at around 225 K and 150 K, and they are strongly correlated with the magnetic ordering in the mixed-phase BFO film. Moreover, through the effective spin-lattice coupling, the evolution of the T/R polymorph is changed by the magnetic cooling process at low temperatures. This study provides a pathway to modulate phonon behaviors by magnetic fields in a highly strained system. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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