OsO₂ is one of those forgotten and ingnored binary oxides in the periodic table. The main reason for this lack of interest is it’s unwanted tendency to form highly toxic and volatile OsO₄, which makes the synthesis and characterisation of samples somewhat challenging. It is fair to say that to publish this paper a number of H&S officers had to be convinced that we would not kill an entire beamline team with an ill adviced heating or sputtering attempt.

Although studying OsO₂ has it’s challenges, there are a number of clear motivations for why we want to know more about it’s characteristics, beyond sheer scientific curiosity. OsO₂ is a transition metal dioxide and it is part of an illustrious group of rutile metallic oxides, including IrO₂, RuO₂, PtO₂, TcO₂, and ReO₂. It is also the parent oxide of the family of osmates, which similar to their cousins the iridates, are starting to show a range of interesting physics, including metal-insulator transitions and exotic magnetic behaviour.

In this work we used a combination of theory and experiment to gain some understanding of the electronic structure using hard and soft X-ray spectroscopy and density functional and many-body perturbation theory. Beyond providing an understanding of all occupied states of OsO₂ we also identified a low-energy plasmon within the valence states. And if you ever wanted to see an intimidating peak fit look no further than the Os 4f/5p core level.

If you’d like to read more about this work, check out the full manuscript in Physical Review Materials.

Now at this point you might rightly ask what all of this has to do with parties. Well, this paper presents a personal milestone for Anna, as it is her 50th peer-reviewed manuscript to be published.