Synthesis of a New Ruthenate Ba26Ru12O57

Jeong-Eun Lee,Ulrich Burkhardt,Alexander Christoph Komarek

doi:10.3390/cryst10050355

Abstract

Single crystals of Ba 26 Ru 12 O 57 were grown by the floating zone method. The crystal structure is formed by an alternating stacking of pseudo-hexagonal Ru single layers and double layers. The Ru ions within the double layers are dimerized (Ru 2 O 9 ) whereas the Ru ions within the single layers arrange in a distorted Kagome lattice of trigonal bipyramidally coordinated RuO 5 polyhedra. Additionally, this Kagome lattice is “decorated” with RuO 6 octahedra that are situated in the central free spaces within this Kagome lattice. According to the composition, the oxidation state of most of the Ru ions should be formally close to 5+.

Highlights

Ruthenates exhibit a broad scope of interesting physical properties ranging from itinerant ferromagnetism in SrRuO3 [1] and metamagnetim in Sr3 Ru2 O7 [2,3] to unconventional superconductivity in Sr2 RuO4 [4]
As known for other ruthenates, during the growth of Ba26 Ru12 O57 a larger evaporation of Ru oxide could be observed during the crystal growth which explains the obtained Ba:Ru ratio in the grown single crystal
The crystal structure of Ba26 Ru12 O57 alternatingly consists of layers of single Ru ions and of layers of dimerized Ru-ions located in face sharing octahedra which are denoted in Figure 4 as layers

Summary

Introduction

Ruthenates exhibit a broad scope of interesting physical properties ranging from itinerant ferromagnetism in SrRuO3 [1] and metamagnetim in Sr3 Ru2 O7 [2,3] to unconventional superconductivity in Sr2 RuO4 [4] (see the reviews [5,6]). The crystal structure at ambient pressure (nine-layer rhombohedral 9R) Ba1 Ru1 O3 consists of Ru trimers with Ru4+ ions sitting in face sharing Ru-oxygen octahedra [11]. As known for other ruthenates, during the growth of Ba26 Ru12 O57 a larger evaporation of Ru oxide could be observed during the crystal growth which explains the obtained Ba:Ru ratio in the grown single crystal.

Results

Conclusion