The complex oxide Pb0.55 Cd0.45 V2 O5 was synthesized and investigated by means of x-ray powder diffraction, electron diffraction, magnetic susceptibility measurements, and band structure calculations. Its structure is similar to that of M V2 O5 compounds (M=Na, Ca), giving rise to a spin system of coupled S=1/2 two-leg ladders. Magnetic susceptibility measurements reveal a spin gap-like behavior with Δ≈270 K and a spin singlet ground state. Band structure calculations suggest Pb0.55 Cd0.45 V2 O5 to be a system of weakly coupled dimers in perfect agreement with the experimental data. Pb0.55 Cd0.45 V2 O5 provides an example of the modification of the spin system in layered vanadium oxides by cation substitution. Simple correlations between the cation size, geometrical parameters, and exchange integrals for the M V2 O5 -type oxides are established and discussed.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 25 Sep 2007|