A new triclinic modification of the pyrochlore-type KOs2O6 superconductor

TL;DR

This paper reports the synthesis and structural analysis of a new triclinic modification of the superconductor KOs2O6, revealing its unique structure and stability under high pressure.

Contribution

It introduces a novel triclinic structural form of KOs2O6 synthesized via high pressure, expanding understanding of its structural diversity.

Findings

New triclinic KOs2O6 structure determined by X-ray diffraction

Stable up to 32.5 GPa under high pressure

Quantum calculations performed on the new and cubic phases

Abstract

A new modification of KOs2O6, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1)A, b=6.4519(2)A, c=7.2356(2)A, space group P-1, no.2) was synthesized employing high pressure technique. Its structure was determined by single-crystal X-ray diffraction. The structure can be described as two OsO6 octahedral chains relating to each other through inversion and forming big voids with K atoms inside. Quantum chemical calculations were performed on the novel compound and structurally related cubic compound. High-pressure X-ray study showed that cubic KOs2O6 phase was stable up to 32.5(2) GPa at room temperature.