Less well known are other higher titanium oxides -- those with a higher number of titanium and oxygen atoms than TiO -- that are now the subject of intensifying research due to their potential use in next-generation electronic devices.
Now, researchers at Tokyo Tech have reported superconductivity in two kinds of higher titanium oxides prepared in the form of ultrathin films.
With a thickness of around 120 nanometers, these materials reveal properties that are only just beginning to be explored.
"We succeeded in growing thin films of Ti4O7 and γ-Ti3O5 for the first time," says Kohei Yoshimatsu, lead author of the paper published in Scientific Reports.
Until now, the two materials had only been studied in bulk form, in which they behave as insulators -- the opposite of conductors.
The thin films are epitaxial, meaning that they have a well-aligned crystalline structure (see Figure 1).