Optical studies of lattice and charge excitations in La-1.2(Sr1.8-xCax)Mn2O7
Journal
Journal of Applied Physics
Journal Volume
93
Journal Issue
10
Pages
6894-6896
Date Issued
2003
Author(s)
Abstract
Optical and Raman-scattering studies of layered La1.2(Sr1.8−xCax)Mn2O7 manganites are presented as a function of temperature and doping (x=0.0, 0.4, 0.6, and 0.8). The substitution of Ca2+ for Sr2+ leads to the suppression of the low-frequency optical spectral weight with decreasing Tc. Moreover, the observed anomalies of the Raman phonon parameters near Tc are most likely due to a strong spin-phonon coupling caused by the oxygen phonon modulation of the Mn–Mn spin exchange interaction. Our results provide important insight into the interplay of lattice, spin, and charge dynamics in these materials.
Type
journal article