Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2003-02-04
Physics
Condensed Matter
Strongly Correlated Electrons
19 pages of text, 30 Figs. and 63 Refs
Scientific paper
We report detailed systematic measurements of the spatial variation in electronic states in the high T{c} superconductor La{2-x}Sr{x}CuO{4} (0.04<= x <= 0.16) using {63}Cu NQR for {63}Cu isotope enriched poly-crystalline samples. We demonstrate that the spatial variation in local hole concentration {63}x{local} given by {63}x{local} = x +/- {63}Dx{local}, where x is the nominal hole concentration and {63}Dx{local} is defined as the amplitude (or extent) of the spatial variation, is reflected in the frequency dependence of the spin-lattice relaxation rate {63}1/T{1} across the inhomogeneous linebroadening of the {63}Cu NQR spectrum. By using high precision measurements of the temperature dependence of {63}1/T_{1} at various positions across the {63}Cu NQR lineshape, we demonstrate that {63}Dx{local} increases below 500 - 600 K and reaches values as large as {63}Dx{local} / x ~ 0.5 in the temperature region > 150 K. By incorporating the random positioning of {+2}Sr donor ions in the lattice in a novel approach, a lower bound to the length scale of the spatial variation {63}R{patch} is deduced by fitting the entire {63}Cu NQR spectrum (including the ``B'' -line) using a patch-by-patch distribution of the spatial variation {63}x{local} with the patch radius {63}R_{patch} > 3.0 nm as the only free parameter. A corresponding upper bound to the amplitude of the spatial variation {63}Dx{patch} (~ 1/{63}R_{patch}) is deduced within the model, and consistent results are found with {63}Dx{local} . We also deduce the onset temperature T{Q} (> 400 K) for local orthorhombic lattice distortions which, in the region x > 0.04, is found to be larger than the onset temperature of long range structural order.
Hunt A. W.
Imai Takayuki
Singer Philip M.
No associations
LandOfFree
{63}Cu NQR Study of the Inhomogeneous Electronic State in La{2-x}Sr{x}CuO{4} does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with {63}Cu NQR Study of the Inhomogeneous Electronic State in La{2-x}Sr{x}CuO{4}, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and {63}Cu NQR Study of the Inhomogeneous Electronic State in La{2-x}Sr{x}CuO{4} will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-269294