https://doi.org/10.1140/epjb/e2005-00245-9
Symmetry-dependent Mn-magnetism in Al69.8Pd12.1Mn18.1
Laboratorium für Festkörperphysik, ETH Zürich,
8093 Zürich, Switzerland
Corresponding author: a gavilano@solid.phys.ethz.ch
Received:
23
September
2004
Revised:
17
June
2005
Published online:
11
August
2005
We investigated the stability of magnetic moments in
Al69.8Pd12.1Mn18.1. This alloy exists in both, the
icosahedral (i) and the decagonal (d) quasicrystalline form.
The transition from the i- to the d-phase is achieved by a
simple heat treatment. We present the results of measurements of
the 27Al NMR-response, the dc magnetic susceptibility, and
the low-temperature specific heat of both phases. In the
icosahedral compound, the majority of the Mn ions carries a
magnetic moment. Their number is reduced by approximately a factor
of two by transforming the alloy to its decagonal variety. For
both compounds, we have indications for two different local
environments of the Al nuclei. The first reflects a low density of
states of conduction electrons and a weak coupling of the Al
nuclei to the Mn-moments. The second type of environment implies a
large d-electron density of states at the Fermi level and a
strong coupling to the magnetic Mn moments. Spin-glass freezing
transitions are observed at K for the
decagonal, and
K for the icosahedral phase.
PACS: 61.44.Br – Quasicrystals / 76.60.-k – Nuclear magnetic resonance and relaxation / 75.50.Lk – Spin glasses and other random magnets
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005