Phase equilibria in the BaO-MgO-Ta2O5 system

被引：16

作者：

Kolodiazhnyi, Taras ^{[1
]}

Belik, Alexei A. ^{[2
]}

Ozawa, Tadashi C. ^{[2
]}

Takayama-Muromachi, Eiji ^{[1
,2
]}

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050044, Japan

[2] Int Ctr Mat Nanoarchitecton, Tsukuba, Ibaraki 3050044, Japan

来源：

JOURNAL OF MATERIALS CHEMISTRY | 2009年 / 19卷 / 43期

基金：

日本学术振兴会;

关键词：

MICROWAVE DIELECTRIC-PROPERTIES; TETRAGONAL TUNGSTEN BRONZE; BA(MG1/3TA2/3)O-3 CERAMICS; HEXAGONAL PEROVSKITES; CRYSTAL-CHEMISTRY; CATION; NONSTOICHIOMETRY; MG; BA(ZN1/3NB2/3)O-3; ZN;

D O I：

10.1039/b912485c

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：

We report on the phase relation in the BaO-MgO-Ta2O5 system equilibrated at 1450 degrees C. We found three ternary phases, namely 3: 1: 1 perovskite Ba3MgTa2O9, 9:1:7 TTB (tetragonal tungsten bronze)type Ba9MgTa14O45 and 4:1:5 Ba4MgTa10O30 closely related to the tungsten bronze structure. Another ternary phase, Ba10Mg0.25Ta7.9O30, with a 10 layer hexagonal perovskite structure can be only obtained after equilibration at 1600 degrees C. MgO solubility in the TTB-like Ba4Ta10O29, BaTa4O11 and Ba6.63Ta34.95O95 does not exceed 2.0 mol%. Only the hexagonal polymorph of the BaTa2O6 phase was found along the Mg4Ta2O9-BaTa2O6 join. Measurements of dielectric properties in the 20 Hz-2 MHz range revealed that Ba9MgTa14O45 has a dielectric constant of 99 with no frequency dispersion and low dielectric loss. We have also clarified several contradictory reports related to the ternary and binary phases in the BaO-MgO-Ta2O5 composition field.

引用

页码：8212 / 8215

页数：4

共 32 条

[1] The crystal structure of Ba8Ta6NiO24: Cation ordering in hexagonal perovskites [J].

Abakumov, AM ;

VanTendeloo, G ;

Scheglov, AA ;

Shpanchenko, RV ;

Antipov, EV .

JOURNAL OF SOLID STATE CHEMISTRY, 1996, 125 (01) :102-107

[2]

Akbas MA, 1998, J AM CERAM SOC, V81, P670, DOI 10.1111/j.1151-2916.1998.tb02388.x

[3] Structure and dielectric properties of perovskite ceramics in the system Ba(Ni1/3Nb2/3)O3-Ba(Zn1/3Nb2/3)O3 [J].

Barwick, M. ;

Azough, F. ;

Freer, R. .

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 2006, 26 (10-11) :1767-1773

[4] Cation ordering, domain growth, and zinc loss in the microwave dielectric oxide Ba3ZnTa2O9-δ [J].

Bieringer, M ;

Moussa, SM ;

Noailles, LD ;

Burrows, A ;

Kiely, CJ ;

Rosseinsky, MJ ;

Ibberson, RM .

CHEMISTRY OF MATERIALS, 2003, 15 (02) :586-597

[5] ABOUT BA4MGTA10O30 AND BA4NITA10O30 COMPOUNDS WITH RELATIONS TO THE TETRAGONAL TUNGSTEN BRONZE AND THE NANB6O15F-TYPE [J].

BRANDT, R ;

MULLERBUSCHBAUM, H .

ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE, 1987, 551 (08) :13-20

[6] SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF REDUCED TERNARY TANTALUM OXIDES IN THE TETRAGONAL TUNGSTEN BRONZE STRUCTURE [J].

FEGER, CR ;

ZIEBARTH, RP .

CHEMISTRY OF MATERIALS, 1995, 7 (02) :373-378

[7] STRUCTURE AND PROPERTIES OF REDUCED BARIUM NIOBIUM OXIDE SINGLE-CRYSTALS OBTAINED FROM BORATE FLUXES [J].

HESSEN, B ;

SUNSHINE, SA ;

SIEGRIST, T ;

FIORY, AT ;

WASZCZAK, JV .

CHEMISTRY OF MATERIALS, 1991, 3 (03) :528-534

[8] SOME COMPOUNDS OF TUNGSTEN-BRONZE TYPE A6B10O30 (B=NB, TI OR NB, W) [J].

IKEDA, T ;

HARAGUCHI, T ;

ONODERA, Y ;

SAITO, T .

JAPANESE JOURNAL OF APPLIED PHYSICS, 1971, 10 (08) :987-+

[9] A Rietveld-analysis program RIETAN-98 and its applications to zeolites [J].

Izumi, F ;

Ikeda, T .

EUROPEAN POWDER DIFFRACTION, PTS 1 AND 2, 2000, 321-3 :198-203

[10]

JANCAR B, COMMUNICATION

← 1 2 3 4 →