NMR, magnetization, and heat capacity studies of the uniform spin-1/2 chain compound Bi6V3O16

We report the local (NMR) and bulk (magnetization and heat capacity) properties of the vanadium-based S = 1/2 uniform spin chain compound Bi6V3O16 (Bi4V2O10.66). In the low-temperature a phase, the magnetic ions (V4+) are arranged in one-dimensional chains. The magnetic susceptibility shows a broad maximum around 50 K signifying a short-range magnetic order. Heat capacity measurements also reveal low-dimensional magnetism. The V-51 magic angle spinning nuclear magnetic resonance measurements clearly show that the magnetic V4+ and nonmagnetic V5+ species are located on different crystallographic sites with no mixed occupation. The spin susceptibility calculated from the shift of the V-51 NMR spectra reproduces the behavior observed in magnetic susceptibility and agrees well with the S = 1/2 uniform spin chain model with J = 113(5) K.