STUDY OF BATIO₃ CERAMICS DOPED WITH Mn AND Ce OR Nb AND Sr

• Main Authors: A.M.Slipenyuk, M.D.Glinchuk, I.P.Bykov, L.P.Yurchenko, V.A.Mikheev, O.A.Frenkel, V.D.Tkachenko, E.P.Garmash
• Format: Article
• Language: English
• Published: Institute for Condensed Matter Physics 2003-01-01
• Series: Condensed Matter Physics
• Subjects: BaTiO₃ ceramics; impurities; positive temperature coefficient of resistivity
• Online Access: http://dx.doi.org/10.5488/CMP.6.2.237

ESR study of BaTiO₃ ferroelectrics doped with cerium or with niobium and strontium, both types of samples being doped with manganese, was performed at room temperature. In the samples of the first type the most intensive line with g-factor 1.9612 was shown to originate from paramagnetic center Ti³⁺-Ce³⁺. The small intensity line was related to Fe³⁺-V_O center, which can be unavoidable impurity in BaTiO₃. In the samples doped with strontium, the six lines intensive spectrum, which corresponds to hyperfine structure of Mn²⁺, was observed. The intensity of the spectrum was shown to decrease with strontium concentration increase. This effect was supposed to be related to the decrease of the grain sizes that results in migration of manganese and, possibly, niobium ions. The influence of these impurities, of their charge states and positions in crystalline lattice of BaTiO₃ on the PTCR effect is discussed.