Chemistry of Layered AB3Si2Sn7O16 Stannides

Abstract

The AB3Si2Sn7O16 phases (sg: P3 ̅m1) are a series of layered semiconductor oxides built from sheets of oxygen-linked A(SnO)6 octahedra and 3d transition metal rich tin-centred kagomé lattices separated by SiO4 tetrahedra. Oxide materials possessing novel geometrically frustrated architectures such as the triangular arrangement of ising spins in the kagomé lattice has garnered considerable recent interest from the materials science field due to the observation of quantum spin liquid states. These states are of interest to scientists, as they will help to connect the gap in understanding between the electronic ground states of matter and crystal structure. In a more practical sense, they are also interesting as they are among the most promising candidates for the building blocks of quantum computers. The novel architecture of SiO4-separated tin and transition metal rich layers in the AB3Si2Sn7O16 structure promises to allow for the synthesis of a significant number of chemically tuneable geometrically-frustrated oxides, however, only limited information on the crystal chemistry of this structure type exists which in turn hinders practical investigation of the links between structure and material properties. This investigation helps to bridge this gap by detailing the changes in chemical and magnetic behaviour as different sites in the tin-oxide framework are systematically substituted by different third, fourth and fifth row elements. Determination of the changes in the final structures and elemental composition will be determined using a combination of powder diffraction measurements and magnetic probes.