Magnetic excitations of the spin-1/2 antiferromagnetic XXZ chain PbCo2V2O8

Here we would like to investigate a new member of the family of effective spin-1/2 antiferromagnetic Heisenberg-Ising chain materials ACo2V2O8, A = Sr, Ba, namely, PbCo2V2O8. It is isostructural to the sister compound SrCo2V2O8 and very similar to BaCo2V2O8, but it has a lower energy scale making it magnetic field phases more accessible with available magnets. We recently determined its magnetic and thermodynamic properties and solved its magnetic structure below the ordering temperature of TN = 3.8 K (see Phys. Rev. B 108, 144432). Here we wish to measure the magnetic spectrum on a single crystal sample (mass of 1 g). PbCo2V2O8 is expected to have a gapped spinon continuum above TN while below TN we expected to see the bound-spinons modes due to the interchain coupling. We therefore plan to measure the spectrum both at 1.8 K and 5 K. In terms of the energy scale we expect excitations extending up to a maximum between 8 and 12 meV.