Uranate is the chemical term for oxide anions of the element uranium. The metal uranium forms several oxides:
Yellowcake, an intermediary product in uranium processing, also contains various uranium oxides.
Some uranium oxides, namely uranium dioxide, have semiconductor properties similar to other semiconductor materials. Its band gap lies at around 1.3 eV. Its Seebeck coefficient is very high, making it a promising material for thermoelectric applications. It is also capable of withstanding high temperatures.
The low level of alpha radiation produced in the material is a cause of electronic noise, causing multiple single-event upsets. Schottky diodes made of uranium oxide and a p-n-p transistor of uranium dioxide were successfully demonstrated in a laboratory. [http://web.ead.anl.gov/uranium/mgmtuses/duuses/semiconductors/index.cfm