Biomedical subjects

D Mayou

Publications and source records attributed to D Mayou.

12 recordsLinked to original sources

PubMed2000

Magnetism in Al(Si)-Mn quasicrystals and related phases.

An extreme sensitivity of the magnetic properties to the atomic structure has been observed in Al(Si)-Mn and Al-Pd-Mn quasicrystals, approximants, and liquids with similar Mn concentrations (of the order of 8%- 20%). Here, we show that the effect of the local environment of the Mn atoms is not sufficient to explain this complex behavior. A new model is presented, which, taking into account Mn-Mn interactions mediated by the conduction electrons over large distances ( 5 A and more), allows one to understand why only a small fraction of the Mn atoms carry a localized magnetic moment in quasicrystals and why a large proportion is magnetic in liquids.

Journal Article↗

PubMed2000

Generalized drude formula for the optical conductivity of quasicrystals

We derive a generalized Drude formula for the optical conductivity of quasicrystals, assuming a diffusion law in a perfect quasicrystal L(t) approximately t(beta), where L(t) measures the spreading of a wave packet in a time t. We show that the so-called Drude peak in the optical conductivity, characteristic of metals, is strongly modified. If beta<1/2 the Drude peak is even replaced by a dip and the dc conductivity increases when disorder increases. An interpretation of the experimental results on icosahedral and decagonal phases is proposed.

Journal Article↗

PubMed1996