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Mechanical relaxation in tetragonal and orthorhombic phases of (Ba,Sr)TiO 3 ceramics
Author(s) -
Wang H. Y.,
Chen L.,
Meng H.,
Xiong X. M.,
Zhang J. X.
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200945097
Subject(s) - tetragonal crystal system , orthorhombic crystal system , relaxation (psychology) , activation energy , materials science , arrhenius equation , ceramic , condensed matter physics , oxygen transport , mineralogy , thermodynamics , oxygen , crystallography , crystal structure , chemistry , composite material , physics , psychology , social psychology , organic chemistry
Two broad relaxation peaks in the tetragonal and orthorhombic phases, respectively, of Ba x Sr 1– x TiO 3 ( x = 0.8 and 1) ceramics were investigated via internal friction and modulus measurements. The activation energy calculated from the Arrhenius relation shows that the relaxation process depends on the thermal history. A possible explanation is proposed that the relaxation during heating is associated with the motion of domain walls, the migration of oxygen vacancies and the interaction between oxygen vacancies and domain walls. In addition, the activation energies of Ba 0.8 Sr 0.2 TiO 3 are smaller than those of BaTiO 3 , possibly resulting from the larger interspaces of the two neighbouring Ba 2+ and Sr 2+ along the c ‐axis.