Abstract
We have investigated electrically active magnetic excitations (electromagnons) in perovskite manganites with the -type (up-up-down-down) spin structure by terahertz spectroscopy. and without magnetic moments, which host collinear sinusoidal, -type, cycloidal, and -type spin orders, are used to examine the systematics of possible electromagnons. Three-peak structures (2.8, 4.3, and 5.6 meV) of magnetic origin show up in the -type phase with little composition dependence of frequencies, making a contrast with the electromagnons observed in the cycloidal-spin phases. One of these electromagnon is ascribed to the zone-edge magnon mode based on the calculated magnon dispersions.
- Received 22 January 2010
DOI:https://doi.org/10.1103/PhysRevB.81.100413
©2010 American Physical Society