Chemical suppression of intertwined density waves in Cu-substituted La<sub>4</sub>Ni<sub>3-x</sub>Cu<sub>x</sub>O<sub>10+δ</sub>
Oral-In-person
Abstract
Superconductivity in La4Ni3O10 has been reported when intertwined spin- and charge-density-wave (SDW/CDW) order is suppressed through hydrostatic pressure, suggesting a link between density-wave and pairing. We investigate whether chemical tuning can achieve a similar effect under ambient conditions. Polycrystalline La4Ni3-xCuxO10+δ (0 ≤ x ≤ 0.7) was synthesized, with Cu doping increasing the p-type carriers in the system; superconductivity was not observed.
Across the series we find a near-linear suppression of the density-wave transition temperature Tdw with x and a concurrent enhancement of the nominal hole concentration inferred from RH(T). For x ≥ 0.15, the sharp resistive anomaly at Tdw becomes undetectable while a magnetic signature in χ(T) persists, indicating a partial decoupling of spin and charge sectors and the likely survival of short-range spin correlations in the absence of a strong resistive signature. Structural refinements reveal small but systematic changes in octahedral distortions and interlayer spacing.
Combining transport and magnetism, we construct an x–T phase diagram that quantifies the progressive destabilization of the coupled SDW/CDW state by Cu substitution and oxygen control. Superconductivity is not observed between 1.8 and 300 K for any x studied, indicating that suppression of the density-wave order alone is insufficient for stabilizing a superconducting phase. Our results establish a chemically simple route for suppressing the density-wave transition in trilayer nickelates.
Across the series we find a near-linear suppression of the density-wave transition temperature Tdw with x and a concurrent enhancement of the nominal hole concentration inferred from RH(T). For x ≥ 0.15, the sharp resistive anomaly at Tdw becomes undetectable while a magnetic signature in χ(T) persists, indicating a partial decoupling of spin and charge sectors and the likely survival of short-range spin correlations in the absence of a strong resistive signature. Structural refinements reveal small but systematic changes in octahedral distortions and interlayer spacing.
Combining transport and magnetism, we construct an x–T phase diagram that quantifies the progressive destabilization of the coupled SDW/CDW state by Cu substitution and oxygen control. Superconductivity is not observed between 1.8 and 300 K for any x studied, indicating that suppression of the density-wave order alone is insufficient for stabilizing a superconducting phase. Our results establish a chemically simple route for suppressing the density-wave transition in trilayer nickelates.
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Publication: Manuscript Under Review
Presenters
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Stephen Zhang
- Princeton University