Two researchers play with nanostructures in a fun, fertile physics playground: the space between two things.
The work by Dagan et. al. explores the emergence and coexistence of superconductivity and magnetism at the interface between insulating, non-magnetic LaAlO3 and SrTiO3 nanowires at low temperatures. The effect of the antiparallel magnetic order on the resistance of the 50 nm wide patterned wires follows the form of giant magnetoresistance (GMR) at low applied magnetic fields.
Here we study the microstructural and transport properties of Co-Ba122 thin films in which secondary non-superconducting phases have been introduced during film growth in two different ways: first by using a Co-Ba122 target with a small amount of oxygen, second by alternating two different targets: a clean CoBa122 and an undoped Ba122 target.
A novel approach combining pulsed field optical FBG strain measurements in world-class magnets, with Density Functional based calculations to pinpoint the peculiar nanopantograph mechanism behind the magnetoelastic coupling, allows researchers to conclude that magnetic field and pressure are alternative ways to tune the quantum properties of the Shastry-Sutherland compound SrCu2(BO3)2
Scientists explore using one magnet to disrupt the field of another.
Ni3TeO6 provides a new approach to coupling magnetism to ferroelectricity with a record large response. We measured this material's magnetic and electric properties across an extended range of temperature and magnetic field and compared with theoretical calculations to extract a model that describes the underlying reason for a large magnetoelectric coupling. High magnetic fields were key to establishing the magnetic Hamiltonian. This work is motivating the discovery of further 3d-4d oxide materials with large magnetoelectric couplings.
MagLab users have employed a combination of ab-initio theory and a newly developed high-pressure, high-field ferromagnetic resonance technique, which is uniquely sensitive to anisotropic magnetic interactions, to gain insights into the importance of spin-orbit coupling effects in a range of organic materials where this effect is usually considered to be small. The findings may be applicable to topics as diverse as spintronics and topological spin phases.
Discovery of a new kind of electron spin superstructure in crystals opens the tantalizing prospect of finding other emergent exotic phases.
Square-planar high-spin Fe(II) molecular compounds are rare. Using an easily modifiable pincer-type ligand, the successful synthesis of the first compound of this type that breaks the FeO4 motif was achieved, and the first spectroscopic evidence that the geometry and spin state persist in solution was obtained.
Grain boundaries in BaFe2As2 (122), which is an iron-based superconductor, block current flow. This study, which was a collaboration with a group at Northwestern University, used a Local Electrode Atom Probe (LEAP), which is a relatively new experimental tool, to make a 3-D atom-by-atom reconstruction of a region of a 122 sample that included a grain boundary. The data showed that the chemical composition varied across the grain boundary and in that oxygen was present at the grain boundaries. These variations in composition may contribute to grain boundary's reduced current carrying capacity.