Magnetic Properties of the low dimensional spin system (VO)${}_2$P${}_2$O${}_7$: ESR and susceptibility

Abstract

Experimental results on magnetic resonance (ESR) and magnetic susceptibility are given for single crystalline (VO)${}_2$P${}_2$O${}_7$. The crystal growth procedure is briefly discussed. The susceptibility is interpreted numerically using a model with alternating spin chains. We determine $J$=51 K and $\delta$=0.2. Furthermore we find a spin gap of $\approx 6$meV from our ESR measurements. Using elastic constants no indication of a phase transition forcing the dimerization is seen below 300 K.

7 pages, REVTEX, 7 figures