Browsing by Author "Huecker, M."

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Charge order and low frequency spin dynamics in lanthanum cuprates revealed by Nuclear Magnetic Resonance
(2010-10-01)
Grafe, H. -J.
;
Curro, N. J.
;
Young, B. L.
;
Vyalikh, A.
;
Vavilova, J.
We report detailed O-17, La-139, and Cu-63,Cu-65 Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) measurements in a stripe ordered La1.875Ba0.125CuO4 single crystal and in oriented powder samples of La1.8-x Eu0.2Sr (x) CuO4. We observe a partial wipeout of the O-17 NMR intensity and a simultaneous drop of the O-17 electric field gradient (EFG) at low temperatures where the spin stripe order sets in. In contrast, the Cu-63,Cu-65 intensity is completely wiped out at the same temperature. The drop of the O-17 quadrupole frequency is compatible with a charge stripe order. The O-17 spin lattice relaxation rate shows a peak similar to that of the La-139, which is of magnetic origin. This peak is doping dependent and is maximal at x a parts per thousand 1/8.
Charge order and low frequency spin dynamics in lanthanum cuprates revealed by Nuclear Magnetic Resonance
(2010-10-01)
Grafe, H. -J.
;
Curro, N. J.
;
Young, B. L.
;
Vyalikh, A.
;
Vavilova, J.
We report detailed (17)O, (139)La, and (63,65)Cu Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) measurements in a stripe ordered La(1.875)Ba(0.125)CuO(4) single crystal and in oriented powder samples of La(1.8-x) Eu(0.2)Sr (x) CuO(4). We observe a partial wipeout of the (17)O NMR intensity and a simultaneous drop of the (17)O electric field gradient (EFG) at low temperatures where the spin stripe order sets in. In contrast, the (63,65)Cu intensity is completely wiped out at the same temperature. The drop of the (17)O quadrupole frequency is compatible with a charge stripe order. The (17)O spin lattice relaxation rate shows a peak similar to that of the (139)La, which is of magnetic origin. This peak is doping dependent and is maximal at x a parts per thousand 1/8.