Search for Spin Density Wave in Single Crystals of Lithium Purple Bronze (Li0.9Mo6O17)

Lithium Purple Bronze, Li0.9Mo6O17 (LiPB), is a quasi-one-dimensional metal believed to be a Luttinger liquid. Near 30 K it experiences a crossover in dimension and superconducts below 2 K [1]. Hall effect measurements reveal an extremely low charge-carrier density of 10^17 cm^-3 [2]. Many as-grown crystals are non-superconducting with even lower charge-carrier densities of 10^14 cm^-3 [2]. We postulate that LiPB may reside at the boundary between superconductivity and spin-density wave (SDW) ordering due to density-wave reconstruction of the Fermi surface. Many measurements offer evidence against charge-density wave (CDW) ordering, motivating our investigation of SDW ordering [3,4]. Results of our search for a SDW in single crystals of LiPB using the CORELLI instrument at the ORNL Spallation Neutron Source (SNS) will be presented.  

[1] C. A. M. Dos Santos, et al., Dimensional Crossover in the Purple Bronze, Phys. Rev. Lett. 98 (2007) 266405. 

[2] Cohn, J. L, et al., Superconductivity at carrier density 10^17 cm^-3 in quasi-one-dimensional Li0.9Mo6O17, Phys. Rev. B, 108, (2023) L100512.

[3] G. Wu, et al., Direct observation of charge state in the quasi-one-dimensional conductor Li0.9Mo6O17, Sci. Rep. 6 (2016) 20721.

[4] J. Choi, et al., Probing localization effects in Li0.9Mo6O17: an optical properties investigation, Phys. Rev. B 69 (2004) 085120.