NMR characterization of spin-½ alternating antiferromagnetic chains in the high-pressure phase of (V O)2P2O7

Local-susceptibility measurements via the NMR shifts of 31P and 51V nuclei in the high-pressure phase of (V O)2P2O7 confirmed the existence of a unique alternating antiferromagnetic chain with a zero-field spin gap of 34 K. The 31P nuclear spin–lattice relaxation rate scales with the uniform spin susceptibility below about 15 K, which shows that the temperature dependences of both the static and dynamical spin susceptibilities become identical at temperatures not far below the spin-gap energy.