25 research outputs found
Increase in cycling stability of doped lithium nickel manganese oxide spinels during charging between 2.0 and 5.0 V
Improved wide operation voltage capability of Fe-, Ti- and F-doped LiNi₀̣₅Mn₁̣₅O₄ spinel cathodes for lithium ion batteries
Influence of synthesis conditions and processing on the cathode performance of 5V-spinel materials. Titanium doping of LiNi₀̣₅Mn₁̣₅O₄ spinel
XPS characterization of iron/fluorine co-doped BST thin films for tunable microwave applications
Design and Tuning of the Electrochemical Properties of Vanadium-Based Cation-Disordered Rock-Salt Oxide Positive Electrode Material for Lithium-Ion Batteries
Electrochemical and in situ investigation of quaternary lithium transition metal fluorides in Li-ion batteries
In-situ X-ray diffraction: time-resolved structure investigation of Li-transition metal-fluorides as cathode materials in Li-ion batteries
Creating a Ferromagnetic Ground State with Tc Above Room Temperature in a Paramagnetic Alloy through Non-Equilibrium Nanostructuring
Materials with strong magnetostructural coupling have complex energy landscapes featuring multiple local ground states, thus making it possible to switch among distinct magnetic-electronic properties. However, these energy minima are rarely accessible by a mere application of an external stimuli to the system in equilibrium state. A ferromagnetic ground state, with Tc above room temperature, can be created in an initially paramagnetic alloy by nonequilibrium nanostructuring. By a dealloying process, bulk chemically disordered FeRh alloys are transformed into a nanoporous structure with the topology of a few nanometer-sized ligaments and nodes. Magnetometry and Mössbauer spectroscopy reveal the coexistence of two magnetic ground states, a conventional low-temperature spin-glass and a hitherto-unknown robust ferromagnetic phase. The emergence of the ferromagnetic phase is validated by density functional theory calculations showing that local tetragonal distortion induced by surface stress favors ferromagnetic ordering. The study provides a means for reaching conventionally inaccessible magnetic states, resulting in a complete on/off ferromagnetic–paramagnetic switching over a broad temperature range