Spin Wave Damping Arising from Phase Coexistence below Τc in Colossal Magnetoresistive La0.7Ca.03MnO3

Published: September 13, 2017

Author(s)

Joel Helton, Susumu K. Jones, Daniel E Parshall, Matthew B. Stone, Dmitry A. Shulyatev, Jeffrey W. Lynn

Abstract

While the spin dynamics of La0.7Cad0.3MnO3 in the ferromagnetic phase are known to be unconventional, previous measurements have yielded contradictory results regarding the damping of spin of Τc=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 non-interacting 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 approximatley 13 {angstrom} in size persisting over a large range of temperatures below Τc.
Citation: Physical Review B
Volume: 96
Issue: 10
Pub Type: Journals

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Keywords

colossal magnetoresistance, ferromagnetic spin waves, spin wave damping
Created September 13, 2017, Updated June 25, 2018