Scientific Highlights
Unconventional magnetic order in the conical state of MnSi
In the temperature-magnetic field phase diagram, the binary metallic compound MnSi exhibits three magnetic phases below Tc ≈ 29K.An unconventional helicoidal phase is observed in zero field. At moderate field intensity a conical phase sets in. Near Tc, in an intermediate field range, a skyrmion lattice phase appears.
Magnetic states of MnP: muon-spin rotation studies
Muon-spin rotation data collected at ambient pressure (p) and at p = 2.42 GPa in MnP were analyzed to check their consistency with various low- and high-pressure magnetic structures reported in the literature. Our analysis con rms that in MnP the low-temperature and low-pressure helimagnetic phase is characterised by an increased value of the average magnetic moment compared to the high-temperature ferromagnetic phase.
Ground state selection under pressure in the quantum pyrochlore magnet Yb2Ti2O7
A quantum spin liquid is a state of matter characterized by quantum entanglement and the absence of any broken symmetry. In condensed matter, the frustrated rare-earth pyrochlore magnets Ho2Ti2O7 and Dy2Ti2O7, so-called spin ices, exhibit a classical spin liquid state with fractionalized thermal excitations (magnetic monopoles).
Room-temperature helimagnetism in FeGe thin films
Chiral magnets are promising materials for the realisation of high-density and low-power spintronic memory devices. For these future applications, a key requirement is the synthesis of appropriate materials in the form of thin films ordering well above room temperature. Driven by the Dzyaloshinskii-Moriya interaction, the cubic compound FeGe exhibits helimagnetism with a relatively high transition temperature of 278 K in bulk crystals.
New magnetic phase in the nickelate perovskite TlNiO3
The RNiO3 perovskites are known to order antiferromagnetically below a material-dependent Néel temperature TN. We report experimental evidence indicating the existence of a second magnetically ordered phase in TlNiO3 above TN = 104K, obtained using nuclear magnetic resonance and muon spin rotation spectroscopy.
Probing current-induced magnetic fields in Au|YIG heterostructures with low-energy muon spin spectroscopy
We investigated the depth dependence of current-induced magnetic fields in a bilayer of a normal metal (Au) and a ferrimagnetic insulator (Yttrium Iron Garnet—YIG) by using low energy muon spin spectroscopy (LE-μSR). This allows us to explore how these fields vary from the Au surface down to the buried Au|YIG interface, which is relevant to study physics like the spin-Hall effect.
Suppression of magnetic excitations near the surface of the topological Kondo insulator SmB6
We present a detailed investigation of the temperature and depth dependence of the magnetic properties of the three-dimensional topological Kondo insulator SmB6, in particular, near its surface. We find that local magnetic field fluctuations detected in the bulk are suppressed rapidly with decreasing depths, disappearing almost completely at the surface.
Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO2
Here we present a study of magnetism in Co0.05Ti0.95O2−δ anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transmission electron microscopy analyses indicate that a high deposition rate leads to a homogeneous microstructure, while a very low rate or postannealing results in cobalt clustering.
Bulk superconductivity at 84 K in the strongly overdoped regime of cuprates
By means of magnetization, specific heat, and muon-spin relaxation measurements, we investigate newly synthesized high-pressure oxidized Cu0.75Mo0.25Sr2YCu2O7.54, in which overdoping is achieved up to p ˜ 0.46 hole/Cu, well beyond the Tc-p superconducting dome of cuprates, where Fermi-liquid behavior is expected.