H all effect and dielectric properties of Mn - doped barium titanate

BaMn Ti O (0# x # 0.01) ceramics have been prepared using a sol–gel method. The Hall coefficient, x 12x 3 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 5 1/ ueRu decreases with increasing Mn 31 41 concentration. We propose that Mn and Mn substitution of Ti can partially trap the conductance electrons. The dielectric constant e of the pellets exhibited a peak at T |110 8C upon heating and the height and position 1 c 21 of this peak depends on the Mn concentration. The Mn incorporated in the oxygen octahedron of the BaTiO3 41 unit cell is in a more centered position than Ti and may, therefore, modify considerably the ferroelectric property.  2002 Elsevier Science B.V. All rights reserved.