Crystal structure and phase stability of the Φ phase in the Al-Mg-Zn system

被引：16

作者：

Berthold, Rico ^{[1
]}

Kreiner, Guido ^{[1
]}

Burkhardt, Ulrich ^{[1
]}

Hoffmann, Stefan ^{[1
]}

Auffermann, Gudrun ^{[1
]}

Prots, Yurii ^{[1
]}

Dashjav, Enkhtsetseg ^{[1
]}

Amarsanaa, Altangerel ^{[1
]}

Mihalkovic, Marek ^{[2
]}

机构：

[1] Max Planck Inst Chem Phys Solids, D-01187 Dresden, Germany

[2] Slovak Acad Sci, Inst Phys, Bratislava 84228, Slovakia

来源：

INTERMETALLICS | 2013年 / 32卷

关键词：

Aluminides; miscellaneous; Ternary alloy systems; Crystal chemistry of intermetallics; Phase diagrams; Ab-initio calculations; ELECTRONIC-STRUCTURE; QUASI-CRYSTALS; APPROXIMANTS;

D O I：

10.1016/j.intermet.2012.08.025

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 equilibria, the homogeneity range, the crystal and electronic structure of the Phi phase in the Al-Mg-Zn system. The homogeneity range is similar at 360 degrees C and 330 degrees C and has a wedgelike shape. Al and Zn vary about 13 at.% and Mg maximal 2.5 at.%. The crystal structure has been characterized by X-ray single crystal structure refinement at two compositions Al23.2Mg54.6Zn22.2 ((Al1.856Mg0.368Zn1.776)Mg-4, Z = 19, oP152, Pbcm, a = 8.9374(7) angstrom, b = 16.812(2) angstrom, c = 19.586(4) angstrom) and Al17.1Mg53.4Zn29.5 (Al1.368Mg0.272Zn2.360)Mg-4, a = 8.8822(3) angstrom, b = 16.7741(7) angstrom, c = 19.4789(8) angstrom). The structure contains four different types of layers stacked along the c axis which can be classified as pentagon-boat, boat, pentagon-triangle and square-triangle tilings. These tilings are decorated by Al and Zn centred icosahedra. The valence band structure can be described by a nearly free electron model except the 3d Zn contributions at lower energy. The large solubility for Al and Zn is caused by substitutional disorder at the icosahedral sites. Total energy calculations indicate, that the homogeneity range at higher temperatures splits up at 0 K into two ordered structures with compositions Al16Mg50Zn34 and Al10Mg50Zn40. (C) 2012 Elsevier Ltd. All rights reserved.

引用

页码：259 / 273

页数：15

共 45 条

[1]

[Anonymous], 2003, STOE WINXPOW VERS 2

[2] THE CRYSTAL STRUCTURE OF THE METALLIC PHASE MG32 (A1,ZN) [J].

BERGMAN, G ;

WAUGH, JLT ;

PAULING, L .

ACTA CRYSTALLOGRAPHICA, 1957, 10 (04) :254-259

[3]

Blatov V.A., 2004, Crystallogr. Rev., V10, P249, DOI [10.1080/08893110412331323170, DOI 10.1080/08893110412331323170]

[4] AN EMPIRICAL CORRECTION FOR ABSORPTION ANISOTROPY [J].

BLESSING, RH .

ACTA CRYSTALLOGRAPHICA SECTION A, 1995, 51 :33-38

[5] IMPROVED TETRAHEDRON METHOD FOR BRILLOUIN-ZONE INTEGRATIONS [J].

BLOCHL, PE ;

JEPSEN, O ;

ANDERSEN, OK .

PHYSICAL REVIEW B, 1994, 49 (23) :16223-16233

[6] PROJECTOR AUGMENTED-WAVE METHOD [J].

BLOCHL, PE .

PHYSICAL REVIEW B, 1994, 50 (24) :17953-17979

[7]

Boettinger WilliamJ., 2007, Methods for Phase Diagram Determination, P151, DOI [10.1016/B978-008044629-5/50005-7, DOI 10.1016/B978-008044629-5/50005-7]

[8] A pentagonal cluster in certain approximants to decagonal quasicrystals [J].

Boström, M ;

Hovmöller, S .

ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE, 2001, 57 (05) :646-651

[9] The crystal structure of the equilibrium Φ phase in Mg-Zn-Al casting alloys [J].

Bourgeois, L ;

Muddle, BC ;

Nie, JF .

ACTA MATERIALIA, 2001, 49 (14) :2701-2711

[10]

Brandenburg K., 2005, CRYSTAL IMPACT GBR

← 1 2 3 4 5 →