Mössbauer Spectroscopy for Solid-State Research
R. Dean Taylor - Capability Leader
The Mössbauer Effect (ME), discovered in 1958 and available at LANL since 1959, is the recoil-free emission and absorption of gamma rays. This surprising nuclear physics event provides a powerful tool to study the environment of certain resonant Mössbauer nuclei in a variety of solid-state hosts. More than 90 γ-ray transitions in about 75 isotopes of over 42 different elements show some ME, but we currently are using only the 57Fe and 119Sn isotopes, mostly in natural abundance absorbers. Typical controlled variables are sample composition, temperature, pressure, and applied magnetic field. From the spectra of the ME nucleus in its environment we may obtain detailed local information such as valence and spin states, magnetization, polarization, electric field gradient, lattice dynamics, phase transformations, and non-equivalent sites. Our recent interests have been focused on the effect of very high applied static pressures on various iron oxides and compounds at pressures up to 1.2 megabars using diamond anvil cells. In magnetite for example, we have shown that either temperature or pressure can drive the normal ↔ inverse spinel transformation. Two cryostats equipped with ME spectrometers and ancillary equipment are available. New experiments can be considered.
National High Magnetic Field Laboratory/NHMFL
Low Energy Spectroscopy