Li${}_2$VO(Si,Ge)O${}_4$, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet

R. Melzi, P. Carretta, A. Lascialfari +4

NMR and magnetization measurements in Li${}_2$VOSiO${}_4$ and Li${}_2$VOGeO${}_4$ are reported. The analysis of the susceptibility shows that both compounds are two-dimensional $S=1/2$ Hei…