Scientific Highlights
Non-Fermi Liquid Behavior Close to a Quantum Critical Point in a Ferromagnetic State without Local Moments
A quantum critical point (QCP) occurs upon chemical doping of the weak itinerant ferromagnet Sc3.1In. Remarkable for a system with no local moments, the QCP is accompanied by non-Fermi liquid behavior, manifested in the logarithmic divergence of the specific heat both in the ferro-and the paramagnetic states, as well as linear temperature dependence of the low-temperature resistivity.
Muonium in Stishovite: Implications for the Possible Existence of Neutral Atomic Hydrogen in the Earth's Deep Mantle
Hydrogen in the Earth's deep interior has been thought to exist as a hydroxyl group in high-pressure minerals. We present Muon Spin Rotation experiments on SiO2 stishovite, which is an archetypal high-pressure mineral. Positive muon (which can be considered as a light isotope of proton) implanted in stishovite was found to capture electron to form muonium (corresponding to neutral hydrogen).
The phase diagram of electron-doped La2-xCexCuO4-δ
Superconductivity is a striking example of a quantum phenomenon in which electrons move coherently over macroscopic distances without scattering. The high-temperature superconducting oxides (cuprates) are the most studied class of superconductors, composed of two-dimensional CuO2 planes separated by other layers that control the electron concentration in the planes. A key unresolved issue in cuprates is the relationship between superconductivity and magnetism.
Competing superconducting and magnetic order parameters and field-induced magnetism in electron-doped Ba(Fe1-xCox)2As2
We have studied the magnetic and superconducting properties of Ba(Fe0.95Co0.05)2As2 as a function of temperature and external magnetic field using neutron scattering and muon spin rotation. Below the superconducting transition temperature the magnetic and superconducting order parameters coexist and compete. A magnetic field can significantly enhance the magnetic scattering in the superconducting state, roughly doubling the Bragg intensity at 13.5T.
Anisotropic Local Modification of Crystal Field Levels in Pr-Based Pyrochlores: A Muon-Induced Effect Modeled Using Density Functional Theory
Although muon spin relaxation is commonly used to probe local magnetic order, spin freezing, and spin dynamics, we identify an experimental situation in which the measured response is dominated by an effect resulting from the muon-induced local distortion rather than the intrinsic behavior of the host compound.
PSI summer school 2015
The PSI summer school 2015 on Condensed Matter Research will be organized at the Lyceum Alpinum in Zuoz, Switzerland from August 15-21, 2015. International experts and PSI staff members will introduce and deepen your knowledge not only on methods but also on those phenomena, which are presently at the forefront of modern solid state physics and chemistry. The school will be followed by hands-on practical training at the PSI large user facilities SINQ, SμS and SLS. Online registration and detailed information is available from the school's webpage.
Coexistence of 3d-Ferromagnetism and Superconductivity in [(Li1-Fex)OH](Fe1-yLiy)Se
Superconducting [(Li1-xFex)OH](Fe1-yLiy)Se (x≈0.2, y≈0.08) was synthesized by hydrothermal methods and characterized by single-crystal and powder X-ray diffrac- tion. The structure contains alternating layers of anti-PbO type (Fe1-yLiy)Se and (Li1-xFex)OH. Electrical resistivity and magnetic susceptibility measurements reveal superconductivity at 43K.
13th International Conference on Muon Spin Rotation, Relaxation and Resonance (μSR2014)
The 13th International Conference on Muon Spin Rotation Relaxation and Resonance (μSR2014), organized by our Laboratory for Muon Spin Spectroscopy in collaboration with the University of Zürich and the University of Fribourg, closed on June 6th in Grindelwald.
PSI summer school 2014
The PSI summer school 2014 on Condensed Matter Research will be organized at the Institut Montana in Zug, Switzerland from August 9-15, 2014. The topic of the school will be 'Exploring time, energy and length scales in condensed matter' and the school will be followed by hands-on practical training at the PSI large user facilities SINQ, SμS and SLS. Online registration and detailed information is available from the school's webpage.