Polymorphism in bismuth stannate: A first-principles study

被引：44

作者：

Walsh, Aron ^{[1
]}

Watson, Graerne W. ^{[1
]}

机构：

[1] Univ Dublin, Trinity Coll, Sch Chem, Dublin 2, Ireland

来源：

CHEMISTRY OF MATERIALS | 2007年 / 19卷 / 21期

关键词：

D O I：

10.1021/cm0714279

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：

From the wide range of Sn-IV-based pyrochlores, Bi2Sn2O7 stands out as a material that deviates from the standard cubic-lattice symmetry. At low temperatures, Bi2Sn2O7 adopts a distorted monoclinic root 2 x root 2 x 2 expansion of the pyrochlore structure (cc-phase) and only favors the cubic lattice (gamma-phase) above 900 K. In this study, we calculate and examine the electronic structure of both the alpha- and gamma-phases of Bi2Sn2O7 and compare them to the results of two regular pyrochlore materials, La2Sn2O7 and Y2Sn2O7. Our analysis highlights the importance of covalent interactions between the electronic states of the metal with O 2p in Bi2Sn2O7, which are not present in the other oxides. The formation of an asymmetric electron density on Bi is observed as the driving force behind the distorted geometry favored by Bi2Sn2O7.

引用

页码：5158 / 5164

页数：7

共 48 条

[1] Ionic and electronic conductivity of Yb2+xTi2-xO7-x/2 materials [J].

Abrantes, J. C. C. ;

Levchenko, A. ;

Shlyakhtina, A. V. ;

Shcherbakova, L. G. ;

Horovistiz, A. L. ;

Fagg, D. P. ;

Frade, J. R. .

SOLID STATE IONICS, 2006, 177 (19-25) :1785-1788

[2]

BADARAU M, 1971, ANN CHIN, P109

[3] ATOMS IN MOLECULES [J].

BADER, RFW .

ACCOUNTS OF CHEMICAL RESEARCH, 1985, 18 (01) :9-15

[4] Local lattice disorder in the geometrically frustrated spin-glass pyrochlore Y2Mo2O7 [J].

Booth, CH ;

Gardner, JS ;

Kwei, GH ;

Heffner, RH ;

Bridges, F ;

Subramanian, MA .

PHYSICAL REVIEW B, 2000, 62 (02) :R755-R758

[5] METAL STANNATES AND THEIR ROLE AS POTENTIAL GAS-SENSING ELEMENTS [J].

COLES, GSV ;

BOND, SE ;

WILLIAMS, G .

JOURNAL OF MATERIALS CHEMISTRY, 1994, 4 (01) :23-27

[6] Molecular dynamics studies of radiation induced phase transitions in La2Zr2O7 pyrochlore [J].

Crocombette, Jean-Paul ;

Chartier, Alain .

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS, 2007, 255 (01) :158-165

[7]

DU HL, 2006, APPL PHYS LETT, P88

[8] α-Bi2Sn2O7 -: a 176 atom crystal structure from powder diffraction data [J].

Evans, IR ;

Howard, JAK ;

Evans, JSO .

JOURNAL OF MATERIALS CHEMISTRY, 2003, 13 (09) :2098-2103

[9] Experimental and theoretical study of the electronic structure of HgO and Tl2O3 -: art. no. 235109 [J].

Glans, PA ;

Learmonth, T ;

Smith, KE ;

Guo, J ;

Walsh, A ;

Watson, GW ;

Terzi, F ;

Egdell, RG .

PHYSICAL REVIEW B, 2005, 71 (23)

[10] On the involvement of the shallow core 5d level in the bonding in HgO [J].

Glans, PA ;

Learmonth, T ;

McGuinness, C ;

Smith, KE ;

Guo, JH ;

Walsh, A ;

Watson, GW ;

Egdell, RG .

CHEMICAL PHYSICS LETTERS, 2004, 399 (1-3) :98-101

← 1 2 3 4 5 →