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Spin structure transition in La(1.6-x)Nd(0.4)Sr(x)CuO(4) superconductors.
1Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Summary
Investigating La(1.6-x)Nd(0.4)Sr(x)CuO(4) single crystals reveals negative magnetoresistance due to spin-flop transitions. Susceptibility studies indicate Nd(3+) dominance, obscuring Cu(2+) spin reorientation.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- La(1.6-x)Nd(0.4)Sr(x)CuO(4) exhibits complex spin structures in its normal state.
- Understanding these spin structures is crucial for developing novel electronic materials.
Purpose of the Study:
- To investigate the field and temperature dependencies of spin structures in La(1.6-x)Nd(0.4)Sr(x)CuO(4) single crystals.
- To elucidate the nature of the spin-flop transition and the role of Nd(3+) and Cu(2+) ions.
Main Methods:
- Magnetoresistance measurements were performed on single crystals.
- Magnetic susceptibility measurements were conducted.
- Data analysis was performed within the framework of crystal-field theory.
Main Results:
- A negative magnetoresistance was observed below the spin-ordering temperature for magnetic fields parallel to the CuO(2) plane.
- This negative magnetoresistance is attributed to a spin-flop transition.
- Anisotropic magnetic susceptibilities were well-described by crystal-field theory.
- Broad peaks in in-plane susceptibilities indicate Nd(3+) dominance.
Conclusions:
- The observed phenomena are consistent with a specific spin structure and a spin-flop transition in the normal state.
- Nd(3+) ions significantly influence the magnetic susceptibility, masking the spin reorientation of Cu(2+) ions.
- Further studies may be needed to directly observe Cu(2+) spin reorientation.
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