Speaker
Dr
Ulrich Wahl
(Instituto Tecnológico e Nuclear)
Description
Solid state physics at ISOLDE aims at the study of the structural, electrical,
optical, magnetic and transport properties related to impurities in a variety of
technologically and fundamentally relevant materials, including semiconductors,
metals, high-Tc superconductors and ceramic oxides.
Rather than providing an extensive overview of the complete solid state physics
activities at ISOLDE, this contribution focuses on some of the high-lights of the
current research, including
- the lattice location of dopants and impurities in wide band gap semiconductors by
means of emission channeling,
- the identification of the chemical identity of optical centers in semiconductors
using photoluminescence studies of radioactive impurities,
- the study of the structural and magnetic properties of Fe in semiconductors by
means of the Moessbauer effect,
- the understanding of magnetic hyperfine fields at impurities on metal surfaces and
within the bulk obtained by means of perturbed angular correlation (PAC),
- the configuration of excess O and F dopants in Hg-based High-Tc superconductors,
- the probing of charge ordering effects in phase transitions of colossal magneto-
resistive oxides.
The talk also includes examples that illustrate the benefit of combining results
from several nuclear methods that characterize the same system.
It will be shown that this is a particular strength of the solid state research
undertaken at ISOLDE and has lead to a significantly better understanding in a
number of cases.
Primary author
Dr
Ulrich Wahl
(Instituto Tecnológico e Nuclear)
