Structure and disorder phenomena of cubic Al39Fe2Pd21 in comparison with related structures

被引：37

作者：

Edler, FJ ^{[1
]}

Gramlich, V ^{[1
]}

Steurer, W ^{[1
]}

机构：

[1] Swiss Fed Inst Technol, Crystallog Lab, CH-8092 Zurich, Switzerland

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 1998年 / 269卷 / 1-2期

关键词：

crystal structure; approximant; icosahedral quasicrystals; Al-Fe-Pd; disorder;

D O I：

10.1016/S0925-8388(97)00619-1

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：

A new ternary phase has been found in the system Al-Fe-Pd and studied by single-crystal X-ray structure analysis. Cubic Al39Fe2Pd21, a=15.515(1) Angstrom, Pearson symbol cF248, space group Fm (3) over bar (No. 202), wR(F-o)=0.054, R(F-o)=0.089, represents a new structure type. Crystals were obtained after annealing for 300 h at 900 degrees C and water quenching. The basic structure motif is a framework of edge-sharing icosahedral cages formed by palladium atoms. The structural relationships with other Al-TM compounds are discussed for several examples. A hitherto unknown ordering scheme in regard to this relationship is observed. A plausible geometrical model was derived for static disorder that concerns certain Al sites. Five different orientations of a cube forming the inner sphere of a TM polyhedron occur randomly in five orientations so that the split positions are located on the vertices of a pentagon-dodecahedron. The structure can also be regarded as an approximant of metastable icosahedral Al-Fe-Pd. (C) 1998 Published by Elsevier Science S.A.

引用

页码：7 / 12

页数：6

共 14 条

[1] QUASI-CRYSTALS AND THEIR APPROXIMANTS - DODECAHEDRAL LOCAL ORDERING VERSUS CANONICAL-CELL DESCRIPTION [J].

DMITRIENKO, VE .

ACTA CRYSTALLOGRAPHICA SECTION A, 1994, 50 :515-526

[2] NEW APPROACHES TO THE CONSTRUCTION OF QUASI-CRYSTALS AND THEIR CUBIC APPROXIMANTS [J].

DMITRIENKO, VE .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 1993, 153 :150-154

[3]

DMITRIENKO VE, 1994, APERIODIC 94

[4]

EDLER FJ, UNPUB

[5] The crystal structure of the binary iridium-aluminum IrAl2.75 and rhodium-aluminum RhAl2.63 phase [J].

Grin, Y ;

Peters, K ;

Burkhardt, U ;

Gotzmann, K ;

Ellner, M .

ZEITSCHRIFT FUR KRISTALLOGRAPHIE, 1997, 212 (06) :439-444

[6]

HALL SR, 1995, XTAL3 4

[7] The crystal structure of the ternary alloy c-Al68Pd20Ru12 [J].

Mahne, S ;

Steurer, W .

ZEITSCHRIFT FUR KRISTALLOGRAPHIE, 1996, 211 (01) :17-24

[8] DIE KRISTALLSTRUKTUR VON MG2CU6AL5 [J].

SAMSON, S .

ACTA CHEMICA SCANDINAVICA, 1949, 3 (07) :809-834

[9]

SHELDRICK GM, 1993, SHELXTL PLUS STRUCTU

[10] QUASI-CRYSTALS IN AL-PD-TRANSITION METAL SYSTEMS PREPARED BY RAPID SOLIDIFICATION [J].

TSAI, AP ;

YOKOYAMA, Y ;

INOUE, A ;

MASUMOTO, T .

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 1990, 29 (07) :L1161-L1164

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