Focused ion beam irradiation on Co/Pt films is utilized to pattern ferromagnetic nanodots at medium ion dose, whereas low ion dose permits controlled modification of the coercivity. This is demonstrated experimentally and mapped to micro-magnetic simulations. Temperature measurements prove the thermal stability of films and nanodots in an application relevant temperature range. Extraordinary Hall-Effect measurements are performed on a ferromagnetic nanodot with a target size of 250 nm in a Hall current device at different temperatures. This verifies the thermal stability and the read-out ability of the magnetic bistable states. Single-domain behavior, the coercivity and the switching field distribution are extracted from the hysteresis loops captured in remanence technique. These properties of ferromagnetic Co/Pt dots fulfill the demands to use the nanomagnets in field-coupled magnetic logic devices. (C) 2011 Elsevier Ltd. All rights reserved.