It can be difficult to find risk free interest rates. You can’t find them under that name in Datastream, so what do you have to choose?
Datastream offers an overview of the instruments they recommend for the main markets, including the Datastream code . This overview is available on the Extranet of Datastream, this is the link. When you have to login use the username and password of Datastream Navigator.
Please note: these series are recommended by Datastream, for your own research purpose you might have to choose other series.