Roentgenium is described as one of the possible d-block metals constituting a correlated electron material (CEM), which is incorporated in an electron switch (CES) for used in memory devices: Memory Devices Formed From Correlated Electron Materials (2018).
Nanoplatelets consisting of metal oxides and/or hydroxides are suggested as fire retardants and as agents for chemical or biological decontamination.
Roentgenium oxide and/or hydroxide are mentioned as being suitable: Nanoplatelet Metal Oxides (2017).
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All patent information has been obtained from Espacenet (European Patent Office).