Caesium sesquioxide is a chemical compound with the formula Cs2O3 or more accurately Cs4O6.
[1][2] Compared to the other caesium oxides, this phase is less well studied,[3] but has been long present in the literature.
[5] The compound is often studied as an example of a Verwey type charge ordering transition at low temperatures.
[6][7][8] There were some theoretical suggestions that Cs4O6 would be a ferromagnetic half metal,[9] but along with the closely related rubidium sesquioxide, experimental results found a magnetically frustrated system.
[10] Electron paramagnetic resonance and nuclear magnetic resonance measurements show a complicated low temperature magnetic behavior that depends on the orientation of the oxygen dimers and superexchange through the caesium atoms.