Spin wave damping arising from phase coexistence below Tc in colossal magnetoresistive La0.7Ca0.3MnO3
| Autor: | Matthew B. Stone, Jeffrey W. Lynn, Susumu Jones, D. Parshall, D. A. Shulyatev, Joel S. Helton |
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| Rok vydání: | 2017 |
| Předmět: |
Physics
Colossal magnetoresistance Condensed matter physics Spin polarization Phonon Transition temperature 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Brillouin zone Ferromagnetism Spin wave 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Energy (signal processing) |
| Zdroj: | Physical Review B. 96 |
| ISSN: | 2469-9969 2469-9950 |
| Popis: | While the spin dynamics of ${\mathrm{La}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_{3}$ in the ferromagnetic phase are known to be unconventional, previous measurements have yielded contradictory results regarding the damping of spin wave excitations. Neutron spectroscopy measurements on a sample with a transition temperature of ${T}_{c}=257$ K, higher than most single crystals, unambiguously reveal an anomalous increase in spin wave damping for excitations approaching the Brillouin zone boundary along the [100] direction that cannot be explained as an artifact due to a noninteracting phonon branch. Spin waves throughout the ($HK0$) plane display a common trend where the spin wave damping is dependent upon the excitation energy, increasing for energies above roughly 15 meV and reaching a full width at half maximum of at least 20 meV. The results are consistent with a model of intrinsic spatial inhomogeneity with phase separated regions approximately 18 \AA{} in size persisting over a large range of temperatures below ${T}_{c}$. |
| Databáze: | OpenAIRE |
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