Investigations of the magnetic and crystal field excitations in orthorhombically distorted perovskites RVO₃ (R=Dy, Tb, Pr,Ce)

Full text: Inelastic neutron scattering experiments have been performed on a series of vanadates, in particular DyVO₃, TbVO₃, PrVO₃, and CeVO₃, to categorise the crystal field and magnetic excitations. The vanadates are isostructural to the multiferroic manganites TbMnO₃ and DyMnO₃, with corner sharing, Jahn-Teller distorted VO₆ octahedra (orthorhombic space group Pbnm). However, they posses a collinear C-type antiferromagnetic structure, instead of an incommensurate spin arrangement as in the manganites. In the vanadates, the antiferromagnetic order sets in below Neel temperatures of T_N = 110 K to 124 K. Using inelastic neutron scattering on single crystals we were able to determine the crystal field spectrum and spin wave dispersion relations independently. In order to determine the nature of the crystal field excitations of these materials and in order to understand how the magnetic and crystal field excitations influence one another, we have theoretically calculated the crystal field excitation spectrum. The results are compared to the crystal field and spin wave excitations in the multiferroic maganites, in order to obtain a deeper understanding of the coupling mechanism between the rare earth elements and the transition metals in RVO₃ and RMnO₃, respectively. (author)