Local lattice instability and superconductivity in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>La</mml:mtext></mml:mrow><mml:mrow><mml:mn>1.85</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Sr</mml:mtext></mml:mrow><mml:mrow><mml:mn>0.15</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Cu</mml:mtext></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>−</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mi>M</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mtext>O</mml:mtext><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>(<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>M</mml:mi><mml:mo>=</mml:mo><mml:mtext>Mn</mml:mtext></mml:mrow></mml:math>, Ni, and Co)
C. J. ZhangNational Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568, JapanH. ŌyanagiNational Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8568, Japan
2009lv
ABI
Abstract
Local lattice structures of ${\text{La}}_{1.85}{\text{Sr}}_{0.15}{\text{Cu}}_{1\ensuremath{-}x}{M}_{x}{\text{O}}_{4}$ ($M=\text{Mn}$, Ni, and Co) single crystals are investigated by polarized extended x-ray absorption fine structure. The local lattice instability at low temperature is described by in-plane Cu-O bond splitting. We find that substitution of Mn for Cu causes little perturbation of local lattice instability while Ni and Co substitution strongly suppresses the instability. The suppression of superconductivity by Cu-site substitution is related to the perturbation of lattice instability, indicating that local lattice instability (polaron) plays an important role in superconductivity.
Not yet translated
Identifiers
Citations and references
Cited by 50 references