Tilo Söhnel (University of Auckland) and collaborators (University of Sydney and ANSTO)
Semiconductors have a wide range of applications in industrial technologies including integrated circuits, memory devices, sensors, solar cells and wearable devices. Their utility stems from unique electrical properties that can be modified through elemental substitution.
Geometrical frustration occurs where a combination of conflicting inter-atomic forces leads to complex structures. The perfect kagomé lattice is an example of geometric frustration and is used to study the effects of frustration on magnetic and electronic properties without interference from lattice imperfections.
Kagomé lattices can be difficult to synthesise, and defects can alter the expected properties.
The researchers established the structural changes that occur for a series of geometrically frustrated iron-silicon-oxide (FeFe3Si2Sn7O16) compounds where magnesium was substituted for iron. The Powder Diffraction (PD) beamline is optimised for experiments on advanced crystalline materials and was used to confirm the structure of the oxide-stannite compounds as well as establish the changes in the unit cell parameters under variable temperatures.
The materials exhibited the geometrically frustrated magnetism characteristic of kagomé lattices. This layered arrangement leads to crystal structure stabilisation and the successful the synthesis of new geometrically frustrated materials for semiconductor applications.
Reference:
Allison MC, Avdeev M, Schmid S, Liu S, Söhnel T and Ling CD.2016. Synthesis, structure and geometrically frustrated magnetism of the layered oxide-stannide compounds Fe(Fe−3-xMnx)Si2Sn7O16. Dalton Transactions 45:9689-9694. https://doi.org/10.1039/C6DT01074A
