Quasi-1D antiferromagnets with S = 1 and S=32: The isostructural compounds AgVP2S6 and AgCrP2S6

Abstract Time-of-flight inelastic scattering from polycrystalline samples of AgVP 2 S 6 and AgCrP 2 S 6 has revealed characteristic features of integer and half-integer spin antiferromagnetic chains. In the S = 1 system we have followed the temperature dependence of the Haldane-gap mode in a wide temperature range. The staggered susceptibility compares well with numerical calculations and confirms the exchange-energy scale determined earlier. The spin-wave velocity of the S = 3 2 system suggests a close resemblance to the S = 1 2 case.