Optical probe of charge-spin-lattice dynamics in half-doped La1.5Sr0.5NiO4
Abstract
We have investigated the charge-spin-ordering transition in La1.5Sr0.5NiO4 by measurements of Raman and optical conductivity spectra. The checkerboard-type charge ordering below ∼400 K can be probed by activated phonon (A1g and Eu) and two-magnon (B1g) modes in the infrared and Raman spectra as well as by formation of pseudogaps in the optical conductivity spectra. Besides, another B2g Raman mode emerges below 150 K together with reduction of the optical gap, which can be attributed to another ordering process, i.e., the stripe formation.
- Publication:
-
Physical Review B
- Pub Date:
- January 2003
- DOI:
- 10.1103/PhysRevB.67.014414
- Bibcode:
- 2003PhRvB..67a4414Y
- Keywords:
-
- 71.27.+a;
- 71.45.Lr;
- 75.30.Fv;
- 78.30.-j;
- Strongly correlated electron systems;
- heavy fermions;
- Charge-density-wave systems;
- Spin-density waves;
- Infrared and Raman spectra