Hall effect and dielectric properties of Mn-doped barium titanate

BaMnxTi1-xO3 (0 less than or equal to x less than or equal to 0.01) ceramics have been prepared using a sol-gel method. The Hall coefficient, leakage conductance and dielectric constant were measured. The Hall effect confirms that the charge carriers of the ceramics are electrons, and the electronic concentration n = 1/\eR\ decreases with increasing. Mn4+ concentration. We propose that Mn3+ and Mn4+ substitution of Ti can partially trap the conductance electrons. The dielectric constant e, of the pellets exhibited a peak at T-c similar to 110 degreesC upon heating and the height and position of this peak depends on the Mn concentration. The Mn2+ incorporated in the oxygen octahedron of the BaTiO3 unit cell is in a more centered position than Ti4+ and may, therefore, modify considerably the ferroelectric property. (C) 2002 Elsevier Science B.V. All rights reserved.