  Features of thermally-activated magnetization switching have been studied in
a FeCoB nanomagnet using the N\'eel model. A method of a high-precision
measurement of the coercive field, retention time, {\Delta} and the size of the
switching nucleation domain has been proposed and experimentally demonstrated
using a Hall-probe setup. A high measurement precision, repeatability and
reliability are the features of the proposed method. The dependency of the
parameters of thermally-activated magnetization switching on the gate voltage
and the bias current were studied.
