Coexistence of long-range magnetic ordering and singlet ground state in the spin-ladder superconductor SrCa13Cu24O41
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Date
2013-11-26
Journal Title
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Publisher
American Physical Society
Abstract
A long-range magnetic order was discovered in the quasi-one-dimensional spin-ladder compound SrCa13Cu24O41 by susceptibility, specific heat, and neutron diffraction experiments. The temperature dependence of the magnetic Bragg peak intensity could be well fitted to the power law with a transition temperature TN = 4.23 K and a critical exponent β = 0.28, indicating a three-dimensional phase transition for a low-dimensional magnet. A computer program was coded and found two possible magnetic structure models fitting best with all the observed magnetic peaks. These models suggest the spin-ladder sublattice is magnetically ordered with Cu moments aligning along the a axis. The spin interactions are primarily antiferromagnetic along rungs and legs, while there are ferromagnetic clusters along legs. Surprisingly, the singlet-triplet spin-gap excitation is observable above and below TN, indicating a coexistence of the spin-singlet ground state and long-range magnetic ordering state in this compound. © 2013 American Physical Society.
Description
Keywords
Neutron diffraction, Temperature dependence, Magnets, Spin, Heat, Antiferromagnetic materials
Citation
Deng, G., Kenzelmann, M., Danilkin, S., Studer, A. J., Pomjakushin, V., Imperia, P., Pomjakushina, E., & Conder, K. (2013). Coexistence of long-range magnetic ordering and singlet ground state in the spin-ladder superconductor SrCa13Cu24O41. Physical Review B, 88(17), 174424. doi:10.1103/PhysRevB.88.174424