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Title: Ni-induced local distortions in La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4} and their relevance to T{sub c} suppression: An angular-resolved XAFS study

Abstract

We present results from angular-resolved x-ray-absorption fine-structure (XAFS) measurements at the Ni, La, and Sr K edges of oriented powders of La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4}, with y=0.01, 0.03, 0.06. A special magnetic alignment procedure allowed us to measure pure c- and ab-oriented XAFS at the Ni K edge in identical fluorescence geometries. Both the x-ray-absorption near-edge structure and the XAFS unequivocally show that the NiO{sub 6} octahedra are contracted along the c axis by {approx}0.32{angstrom} relative to CuO{sub 6} octahedra while the in-plane distances of NiO{sub 6} and CuO{sub 6} octahedra are the same within 0.01{angstrom}. The NiO{sub 6} octahedral contraction drives the average c axis contraction measured by diffraction with increasing content of Ni. The local c axis shows strong spatial fluctuations, due to the different NiO{sub 6} and CuO{sub 6} octahedral configurations and the stronger bonding of a La{sup 3+} ion than a Sr{sup 2+} ion to the O(2) apical oxygens of such octahedra. We discuss the relevance of these findings to the mechanisms of loss of superconductivity at y{approx}0.03 and hole localization above y{approx}0.05 by Ni dopants.

Authors:
; ; ;
Publication Date:
Sponsoring Org.:
(US)
OSTI Identifier:
40277529
DOE Contract Number:  
FG03-98ER45681; W-31-109-Eng-38
Resource Type:
Journal Article
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 64; Journal Issue: 10; Other Information: DOI: 10.1103/PhysRevB.64.104510; Othernumber: PRBMDO000064000010104510000001; 029134PRB; PBD: 1 Sep 2001; Journal ID: ISSN 0163-1829
Publisher:
The American Physical Society
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALIGNMENT; BONDING; CONTRACTION; DIFFRACTION; FINE STRUCTURE; FLUCTUATIONS; FLUORESCENCE; SUPERCONDUCTIVITY

Citation Formats

Haskel, Daniel, Stern, Edward A, Polinger, Victor, and Dogan, Fatih. Ni-induced local distortions in La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4} and their relevance to T{sub c} suppression: An angular-resolved XAFS study. United States: N. p., 2001. Web. doi:10.1103/PhysRevB.64.104510.
Haskel, Daniel, Stern, Edward A, Polinger, Victor, & Dogan, Fatih. Ni-induced local distortions in La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4} and their relevance to T{sub c} suppression: An angular-resolved XAFS study. United States. doi:10.1103/PhysRevB.64.104510.
Haskel, Daniel, Stern, Edward A, Polinger, Victor, and Dogan, Fatih. Sat . "Ni-induced local distortions in La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4} and their relevance to T{sub c} suppression: An angular-resolved XAFS study". United States. doi:10.1103/PhysRevB.64.104510.
@article{osti_40277529,
title = {Ni-induced local distortions in La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4} and their relevance to T{sub c} suppression: An angular-resolved XAFS study},
author = {Haskel, Daniel and Stern, Edward A and Polinger, Victor and Dogan, Fatih},
abstractNote = {We present results from angular-resolved x-ray-absorption fine-structure (XAFS) measurements at the Ni, La, and Sr K edges of oriented powders of La{sub 1.85}Sr{sub 0.15}Cu{sub 1-y}Ni{sub y}O{sub 4}, with y=0.01, 0.03, 0.06. A special magnetic alignment procedure allowed us to measure pure c- and ab-oriented XAFS at the Ni K edge in identical fluorescence geometries. Both the x-ray-absorption near-edge structure and the XAFS unequivocally show that the NiO{sub 6} octahedra are contracted along the c axis by {approx}0.32{angstrom} relative to CuO{sub 6} octahedra while the in-plane distances of NiO{sub 6} and CuO{sub 6} octahedra are the same within 0.01{angstrom}. The NiO{sub 6} octahedral contraction drives the average c axis contraction measured by diffraction with increasing content of Ni. The local c axis shows strong spatial fluctuations, due to the different NiO{sub 6} and CuO{sub 6} octahedral configurations and the stronger bonding of a La{sup 3+} ion than a Sr{sup 2+} ion to the O(2) apical oxygens of such octahedra. We discuss the relevance of these findings to the mechanisms of loss of superconductivity at y{approx}0.03 and hole localization above y{approx}0.05 by Ni dopants.},
doi = {10.1103/PhysRevB.64.104510},
journal = {Physical Review B},
issn = {0163-1829},
number = 10,
volume = 64,
place = {United States},
year = {2001},
month = {9}
}