Synthesis, structure, and electronic properties of the Li(11)RbGd(4)Te(6)O(30) single crystal

Materials with spin dimers have attracted much attention in the last several decades because they could provide a playground to embody simple quantum spin models. For example, the Bose–Einstein condensation of magnons has been observed in TlCuCl(3) with anti-ferromagnetic Cu(2)Cl(6) dimers. In this work, we have synthesized a new kind of single-crystal Li(11)RbGd(4)Te(6)O(30) with Gd(2)O(15) dimers. This material belongs to the rhombohedral system with the lattice parameters: a = b = c = 16.0948 Å and α = β = γ = 33.74°. First-principles calculations indicate that Li(11)RbGd(4)Te(6)O(30) is a wide-bandgap (about 4.5 eV) semiconductor. But unlike many other well studied quantum dimer magnets with an anti-ferromagnetic ground state, the Gd(2)O(14) dimers in Li(11)RbGd(4)Te(6)O(30) show ferromagnetic intra-dimer exchange interactions according to our calculations. Our work provides a new material which could possibly extend the studies of the spin dimers.