Electronic Raman scattering through a stripe ordering transition in La₂₋xSrxNiO₄

• Main Authors: Gnezdilov, V.P., Pashkevich, Yu. G., Yeremenko, A.V., Lemmens, P., Güntherodt, G., Tranquada, J.M., Buttrey, D.J., Nakajima, K.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2002
• Series: Физика низких температур
• Subjects: Магнетизм
• Online Access: http://dspace.nbuv.gov.ua/handle/123456789/130241

We describe the results of electronic Raman scattering experiments in two differently doped single crystals of La₂₋xSrxNiO₄ (x=0.225 and 1/3). In B₁g symmetry a crossover from weakly interacting to pseudogap-like behavior is observed at a charge-ordering temperature Tco. In B₂g symmetry a redistribution of electronic continua with decreasing temperature is accompanied by a loss of spectral weight below Tco in the low-frequency region due to opening of a pseudogap. The slope of the Raman response at vanishing frequencies is investigated, too. Its temperature behavior in B₂g symmetry, which predominantly selects charge carriers with momenta along the diagonals of the NiO₂ bonds, provides clear evidence for one-dimensional charge transport in the charge-ordered phase.