Spin Dynamics in Quasi-One-Dimensional Conductor β-Na0.33V2O5: 51V Nuclear Spin–Lattice Relaxation Measurements

Abstract

The 51 V nuclear spin–lattice relaxation rate 1/ T 1 has been measured in various magnetic fields H to study the spin dynamics in the metallic phase of the quasi-one-dimensional conductor β-Na 0.33 V 2 O 5 , which undergoes the metal–insulator transition at T MI ∼135 K. We observe an H dependence of 1/ T 1 T owing to the spin diffusion that is expected to appear in one-dimensional magnetic systems. The H dependence allows us to separate 1/ T 1 T into the q ∼0 and q ∼2 k F contributions. The q ∼0 and q ∼2 k F contributions at the V2 site are suppressed by the Na order–disorder transition at T Na ∼242 K, whereas the dominant q ∼2 k F contributions at the V3 site are not suppressed at T Na . We discuss the spin dynamics based on the Luttinger liquid theory.