Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 78: Correlated Electrons: Poster Session
TT 78.50: Poster
Donnerstag, 10. März 2016, 15:00–18:30, Poster D
Temperature and polarization dependent Raman measurements of Ca2RuO4 — •Raphael German — II.Physikalisches Institut Köln
Ca2RuO4 is a Mott-like insulator, which undergoes a metal-insulator transition at 357 K and antiferromagnetic ordering at TN = 110 K. Here, we report a temperature and polarization dependent Raman scattering study. Earlier studies claimed a Raman active two-magnon excitation around 100 cm−1. This, however, is incompatible with the results from recent inelastic neutron scattering measurements, which suggest that this mode might be of single magnon nature. Instead, it is more likely that the feature which appears at ∼ 650 cm−1, previously claimed to be due to a charge gap, has a two-magnon origin. Another open question in the interpretation of the Raman spectra is the origin of the high-energy peak at ∼ 1360 cm−1. We will discuss the origin of the Raman peaks in terms of one- and two-magnon processes; magnon-phonon coupling, and possible crystal field excitations.