Abstract
Manganese introduced in BaTiO3 as a substituant of titanium is able to trap the electrons produced during a sintering under a very low oxygen pressure. However it strongly modifies the vibrational and electronic properties of the pure compound. This paper is a short summary of the experimental results obtained by impedance and E.P.R. spectroscopies. A more detailed contribution, including single crystal results, will be reported shortly elswhere.