Effects of "Stripes" on the Magnetic Excitation Spectra of La1.48Nd0.4Sr0.12CuO4

The wave vector(q)- and energy(w)-dependent magnetic excitation spectra c"(q,w), have been studied in the temperature(T) range of 10 K<T<150 K on single crystals of La1.48Nd0.4Sr0.12CuO4, which has the static "stripe" order in the low temperature phase. The incommensurability d of the peak of c"(q,w) found by the q-scans and the peak width Dq exhibit characteristic T-dependences. Observed profiles show clear incommensurate structure even at rather high temperatures. The results indicate that effects of the slowly fluctuating "stripes" exist not only in the low temperature tetragonal (LTT) phase but also in the orthorhombic phase(LTO1) of the present system. The persistence of the local structural characteristics of the low-T phase seems to be important.