Role of Ni and Zr doping on the electrical, optical, magnetic, and structural properties of barium zinc tantalate ceramics

Citation
G. Rong et al., Role of Ni and Zr doping on the electrical, optical, magnetic, and structural properties of barium zinc tantalate ceramics, J MATER RES, 14(10), 1999, pp. 4011-4019
Citations number
36
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS RESEARCH
ISSN journal
08842914 → ACNP
Volume
14
Issue
10
Year of publication
1999
Pages
4011 - 4019
Database
ISI
SICI code
0884-2914(199910)14:10<4011:RONAZD>2.0.ZU;2-F
Abstract
Properties of Ni- and Zr-doped Ba(Zn1/3Ta2/3)O-3 ceramics are reported. The nickel ion has an effective paramagnetic moment of 3.22 +/- 0.05. Optical spectra of Ni-doped Ba(Zn1/3Ta2/3)O-3 are dominated by discrete internal tr ansitions between Ni2+ 3d orbitals. Absorption from the (3)Gamma(2)(F) grou nd state to (4)Gamma(3)(F), (3)Gamma(1)(D), (5)Gamma(1)(D), (4)Gamma(3)(P) excited states occurs at approximately 1.55, 1.75, 2.50, and 2.80 eV, respe ctively. The Ligand field strength of neighboring oxygen ions ranges from a bout 7300 cm(-1) (0.25% Ni) to about 7700 cm(-1) (1.0% Ni). A significant i ncrease in the visible continuum background is correlated with increased ta n delta. This effect is attributed to point defects in the Ni environment, suggesting that point defects play an important role in microwave loss in p ractical dielectric material.