Linda Kerkhoff (Section Crystallography, Institute of Geology and Mineralogy, University of Cologne, Germany)

Recently, lithium ruthenates,Li2RuO3 and Li3RuO4, and the Li2IrO3-modifications attracted considerable attention with exhibiting unconventional magnetism[1-3].

The structures of the three modifications of Li2IrO3 ((α-,β- and γ-Li2IrO3[4-6]) and Li2RuO3[7] consist of a honeycomb-like network,while the main structural components of Li3RuO4 are zigzag chains[8]. The need for high-quality single crystals for further investigations turns all compounds into subjects of crystal growth efforts, which are complemented by DTA and powder-XRD.

Single crystals are grown from the gaseous phase. A modified setup after [9] was realised, in which educts are separated by spacers with spikes, acting as preferred nucleation sites.The place of crystallisation depends on the position of the chemical equilibrium.Moreover, Li2IrO3-modifications show preferred growth conditions. For the first time, the applicability of this setup for the growth of Li3RuO4 is shown.

Currently, single crystals of α-Li2IrO3(1mm),β-Li2IrO3(0,5mm),Li2RuO3(0,6mm) and Li3RuO4(0,1mm) can be grown successfully.

[1]Jackeli & Khaliullin,Phys.Rev.Lett., 102,017205(2009)

[2]Chaloupka et al.,Phys.Rev.Lett., 105,027204(2010).

[3]Manuel et al.,Phys.Rev.B, 84,174430(2011).

[4]O’Malley et al.,J.Solid State Chem., 181,1803–1809(2008).

[5]Biffin et al.,Phys.Rev.B, 90,205116(2014).

[6]Modic et al.,Nat.Commun., 5,4203(2014).

[7]Kobayashi et al.,Solid State Ionics, 82,25-31(1995).

[8]Alexander et al.,J.Mater.Chem., 13,2612-2616(2003).

[9]Freund et al.,Scientific reports, 6,35362(2016).