Influence of impurities on the properties of rare-earth-doped barium-titanate ceramics

被引:104
作者
Glinchuk, MD [1 ]
Bykov, IP
Kornienko, SM
Laguta, VV
Slipenyuk, AM
Bilous, AG
V'yunov, OI
Yanchevskii, OZ
机构
[1] Inst Problems Mat Sci, Dept Mat Special Dielect Properties, UA-03180 Kyiv, Ukraine
[2] VI Vernadskii Inst Gen & Inorgan Chem, Dept Solid State Chem, UA-03680 Kyiv 142, Ukraine
关键词
D O I
10.1039/a909647g
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Investigations of impurity centers, electrical resistivity and microstructure of BaTiO3 ceramics doped with rare-earth ions Y, La, Nd, Sm, Dy and Lu at concentrations x = 0.001-0.005 were carried out. Electron paramagnetic resonance, X-ray diffraction and electron microscopy were used for measurements. The most intense EPR lines were shown to belong to paramagnetic complexes Fe3+-V-O and Ti3+-Ln(3+) (Ln = rare-earth ion, V-O = oxygen vacancy). A change in symmetry of the center Fe3+-V-O at the transition temperature from the ferroelectric to paraelectric phase has been revealed for the first time. Measurements of the dependence of EPR line intensities and electrical resistivity with rare-earth ion concentrations were performed. The observed correlation in their behaviour showed an essential role of the identified paramagnetic complexes in the appearance of BaTiO3 ceramic semiconducting properties and the positive temperature coefficient of resistance (PTCR) effect. The latter effect was at a maximum for x approximate to x(c) where x(c) approximate to 0.002-0.003 is the critical rare-earth ion concentration which determines the excess charge compensation mechanism. Up to x(c), the rare earths investigated, (except for the small ion Lu), substitute for barium, and the main compensation mechanism is an electronic mechanism. At high concentrations (x > x(c)) in the case of large ions (e.g. La), substitution is at barium sites, with the creation of titanium vacancies, whereas intermediate ions (e.g. Y) begin to substitute for titanium. The influence of impurities on the BaTiO3 microstructure, including the grain sizes, is discussed.
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页码:941 / 947
页数:7
相关论文
共 30 条
[1]  
BUSCAGLIA MT, 1998, 9 INT C MOD MAT TECH
[2]  
BUSCAGLIA MT, 1999, AT SIM STUD DOP SUBS
[3]  
BYKOV IP, 1991, FIZ TVERD TELA+, V33, P3459
[4]   ORIGIN OF THE GRAIN-GROWTH ANOMALY IN DONOR-DOPED BARIUM-TITANATE [J].
DROFENIK, M .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1993, 76 (01) :123-128
[5]  
ELIOT WR, 1964, J PHYS CHEM SOLIDS, V25, P1273
[6]   RANDOM-FIELDS AND THEIR INFLUENCE ON THE PHASE-TRANSITIONS IN DISORDERED FERROELECTRICS [J].
GLINCHUK, MD ;
STEPHANOVICH, VA .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1994, 6 (31) :6317-6327
[7]   VALENCY STATES AND DISTRIBUTION OF MANGANESE IONS IN PZT CERAMICS SIMULTANEOUSLY DOPED WITH MN AND NB [J].
GLINCHUK, MD ;
BYKOV, IP ;
KURLIAND, VM ;
BOUDYS, M ;
KALA, T ;
NEJEZCHLEB, K .
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 1990, 122 (01) :341-346
[8]   BARIUMTITANAT ALS SPERRSCHICHTHALBLEITER [J].
HEYWANG, W .
SOLID-STATE ELECTRONICS, 1961, 3 (01) :51-58
[9]   ELECTRON PARAMAGNETIC RESONANCE IN SINGLE CRYSTALS OF BATIO3 [J].
HORNIG, AW ;
REMPEL, RC ;
WEAVER, HE .
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 1959, 10 (01) :1-&
[10]   ELECTRON SPIN RESONANCE OF MN2+ IN BATIO3 SINGLE CRYSTAL [J].
IKUSHIMA, H .
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 1966, 21 (10) :1866-&