Magnetic order and electronic charge transport in the system (Sr 1− xEu x) 2VO 4

Abstract

We report on the preparation and on measurements of the magnetic susceptibility and electronic charge transport properties for samples from the solid solution system (Sr 1− x Eu x ) 2VO 4, which formally is similar to the high temperature superconducting system (La 1− x Sr x ) 2CuO 4. The samples are semiconducting in the whole solid solution range with the maximum electrical conductivity σ=10 2 (Ωcm) -1 close to x=0.25. From the comparison of the temperature dependence of the electrical resistivity and the Seebeck coefficient one finds clear evidence for the polaron character of the charge carriers. Antiferromagnetic long range order is found down to the percolation limit of 60 at% V 3+, for the antiferromagnetic exchange interaction in the VO 2 planes we derive J af=98 K. The magnetic behaviour is consistent with the coexistence of V 3+ and V 3+-local spins within the solid solution range and a weak magnetic coupling between the V 3+ and the V 4+ spins.