Spin dynamics of quasi-one-dimensional spin-ladder system SrCa13Cu24O41 in the long-range magnetic ordering state
Loading...
Date
2018-01-31
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Institute of Physics
Abstract
Sr14-xCaxCu24O41 is a quasi-one-dimensional magnet, which consists of two sublattices: spin ladder and spin chain, forming an incommensurate crystal structure along the c axis, namely, the ladder leg or chain direction. The highly Ca-doped compounds undergo a superconducting phase transition under hydrostatic pressure ~ 3GPa, which is really intriguing since the hole-doped even-leg spin-ladder system was theoretically predicted as superconductors by charge-pairing mechanism through antiferromagnetic interaction on the rungs of spin ladders. In the previous study, we discovered that all compounds with different Ca content have a singlet ground state with a spin-gap ~ 32meV. In the highly Ca-doped sample SrCa13Cu24O41, a long-range magnetic ordering takes place at ~ 4.2K. Interestingly, the singlet spin-liquid state and the long-range magnetic ordering coexist in this compound. In this study, we further investigated its spin dynamics in the ordered phase by using inelastic neutron scattering on PELICAN and SIKA at OPAL. We observed the gapless spin-wave excitation, dispersive along the a and c axes but nondispersive along the b axis, indicating the nature of a 2D magnet. A dynamic model has been proposed to fit the experimental data, indicating three major exchange interactions along rungs (JR), legs (JL) and between neighbor ladders (JInter). This study helps us to understand the origin of the spin liquid ground state in this low-dimensional magnet, in which hole-doping should be attributed to induce the long-range magnetic ordering due to the disorder-induced order effect.
Description
Keywords
Spin, Dynamics, Strontium, Calcium, Copper, Crystal lattices, Doped materials, Phase transformations, Hydrostatics, Measuring instruments, OPAL Reactor, Order-disorder transformations
Citation
Deng, G., Yu, D., Mole, R., Yano, S., Wang, C.-W., Rule, K. C., Gardner, J. S., Luo, H., Li, S., Ulrich, C., Imperia, P., Ren, W., Cao, S., Pomjakushina, E., Conder, K., Kenzelmann, M., & McIntyre, G. J. (2018). Spin dynamics of quasi-one-dimensional spin-ladder system SrCa13Cu24O41 in the long-range magnetic ordering state. Poster presented to the 42nd Annual Condensed Matter and Materials Meeting, Charles Sturt University, Wagga Wagga, NSW, 30th January – 2nd February 2018, (pp. 80). Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2018/Wagga_2018_Conference_Handbook.pdf