Incommensurate stripe order in La{sub 2{minus}{ital x}}Sr{sub {ital x}}NiO{sub 4} with {ital x}=0.225
- Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)
- Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States)
- Materials Science Program, University of Delaware, Newark, Delaware 19716 (United States)
In recent studies of La{sub 2{minus}{ital x}}Sr{sub {ital x}}NiO{sub 4} it has been suggested that ordering of the dopant-induced holes occurs only commensurately at special values of {ital x}, such as 1/3 and 1/2. Commensurate order of both charge and spin densities has also been found in a crystal with {ital x}=0.20. The present neutron scattering study of an {ital x}=0.225 crystal demonstrates that the spin and charge order can also be incommensurate. In fact, the incommensurability is temperature dependent, as observed previously in La{sub 2}NiO{sub 4.125}, indicating that such behavior is intrinsic to the doped NiO{sub 2} layers and not dependent on ordering of the dopant ions. A careful analysis of the unusual variation of peak widths as a function of momentum transfer perpendicular to the planes shows that the charge- and spin-density modulations are tied to the lattice, with the shift in phase of the charge modulations from one layer to the next equal to exactly one in-plane lattice spacing. A comparison of results for a number of samples shows that the charge and spin ordering temperatures vary linearly with hole concentration, with charge order always occurring at higher temperature, clearly indicating that the ordering is driven by the charge. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- Brookhaven National Laboratory
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 388333
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 54; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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