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Neutron scattering study of soft phonons and diffuse scattering in insulating La$_{1.95}$Sr$_{0.05}$CuO$_{4}$

Shuichi Wakimoto·Seunghun Lee·Peter M. Gehring·Robert J. Birgeneau·Gen Shirane
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Abstract

Soft phonons and diffuse scattering in insulating La$_{2-x}$Sr$_{x}$CuO$_4$ ($x=0.05$) have been studied by the neutron scattering technique. The X-point phonon softens from high temperature towards the structural transition temperature $T_{s}=410$ K, and the Z-point phonon softens again below 200 K. The Z-point phonon softening persists to low temperature, in contrast to the behavior observed in the superconducting $x=0.15$ compound, in which the Z-point phonon hardens below $T_c$. The diffuse scattering associated with the structural phase transition at 410 K appears at commensurate positions. These results highlight interesting differences between superconducting and insulating samples.

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Shuichi Wakimoto, Seunghun Lee, Peter M. Gehring, Robert J. Birgeneau, Gen Shirane. 2004-08-24. Neutron scattering study of soft phonons and diffuse scattering in insulating La$_{1.95}$Sr$_{0.05}$CuO$_{4}$. https://doi.org/10.1143/jpsj.73.3413

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