No.
They are too small to use in anything but a drive with a tray.
The reason is that the tray has a way of centering any disc so that they can be read, this also acts as an ejecting mechanism.
Slot loading drives have no way of centering anything but normal sized discs, people who have put mini cds into their drives have been unable to eject them as the drive doesnt properly detect them.
Hope this helps.