Al7+xFe23Ge14-x and Al7+xFe9Ge5-x

Author(s)

Gabriel R. Reisinger, Herta S. Effenberger, Klaus W. Richter

Abstract

The title compounds were synthesised from the pure elements by arc melting and subsequent heat treatment at 800 °C. They were characterised by powder- and single-crystal XRD, their homogeneity ranges were investigated by scanning electron microscopy and EDX from a series of samples with distinct overall compositions. Al

_7+xFe

₂₃Ge

_14-x(−0.8 ≤ x ≤ 1.8, orthorhombic, space group Cmc2

₁, Pearson symbol oC176; a = 7.912 (2), b = 19.786(6), c = 14.769(5) Å) adopts a new crystal structure type, while Al

_7+xFe

₉Ge

_5-x, (−0.7 ≤ x ≤ 3.5, monoclinic, space group C2/m, Pearson symbol mC42; a = 10.147(2), b = 7.5394(12), c = 7.8744(12) Å, β = 108.396(15)°) was found to be isotypic with Fe

₃Ga

₄. Within the accuracy of structure refinements the Fe atoms build an ordered and fully occupied sublattice, whereas extensive mixed occupation between aluminium and germanium atoms is evident. Both compounds exhibit noticeable homogeneity ranges based on extensive (Al,Ge) substitutions. Their crystal structures are related to the Fe

₆Ge

₅-structure type (monoclinic, space group C2/m, Pearson symbol mC44). Structural features and relations are discussed; homogeneity ranges as well as the corresponding lattice parameters are given.

Organisation(s)

Department of Functional Materials and Catalysis, Department of Mineralogy and Crystallography

Journal

Journal of Alloys and Compounds

Volume

693

Pages

692-699

No. of pages

8

ISSN

0925-8388

DOI

https://doi.org/10.1016/j.jallcom.2016.09.236

Publication date

02-2017

Peer reviewed

Yes

Austrian Fields of Science 2012

104003 Inorganic chemistry, 104017 Physical chemistry, 104011 Materials chemistry, 105113 Crystallography

Keywords

ASJC Scopus subject areas

Mechanics of Materials, Mechanical Engineering, Metals and Alloys, Materials Chemistry

Portal url

https://ucrisportal.univie.ac.at/en/publications/c8934dcd-1d99-4a23-8160-4bb57e7aed53