Interacting Trimagnetic Ensembles for Enhanced Magnetic Resonance Transverse Relaxivity.

An ensemble of nanosystems can be considered to improve magnetic resonance imaging (MRI) transverse relaxivity. Herein, an interacting superparamagnetic competing structure of an isotropic-anisotropic trimagnetic hybrid nanosystem, γ-FeO@δ-MnO@NiFeO, is considered for MRI relaxivity exploration. The interacting superparamagnetic system reveals fascinating dynamic magnetic behavior, where flower-shaped two-dimensional flakes are decorated over nanoparticles.

Evidence of Strong Orbital-Selective Spin-Orbital-Phonon Coupling in CrVO_{4}.

Coupling of orbital degree of freedom with a spin exchange, i.e., Kugel-Khomskii-type interaction (KK), governs a host of material properties, including colossal magnetoresistance, enhanced magnetoelectric response, and photoinduced high-temperature magnetism.

Integrative Modulation of Magnetic Resonance Transverse and Longitudinal Relaxivity in a Cell-Viable Bimagnetic Ensemble, γ-FeO@ZnFeO.

The potential application of magnetic nanosystems as magnetic resonance imaging (MRI) contrast agents has been thoroughly investigated. This work seeks to attain robust MRI-contrast efficiency by designing an interacting landscape of a bimagnetic ensemble of zinc ferrite nanorods and maghemite nanoparticles, γ-FeO@ZnFeO. Because of competing spin clusters and structural anisotropy triggered by isotropic γ-FeO and anisotropic ZnFeO, γ-FeO@ZnFeO undergoes the evolution of cluster spin-glass state as evident from the critical slowing down law.

Quasi-One-Dimensional Fermi Surface Nesting and Hidden Nesting Enable Multiple Kohn Anomalies in α-Uranium.

The topology of the Fermi surface controls the electronic response of a metal, including charge density wave (CDW) formation. A topology conducive for Fermi surface nesting (FSN) allows the electronic susceptibility χ_{0} to diverge and induce a CDW at wave vector q_{CDW}. Kohn extended the implications of FSN to show that the imaginary part of the lattice dynamical susceptibility χ_{L}^{''} also responds anomalously for all phonon branches at q_{CDW}-a phenomenon referred to as the Kohn anomaly.

Magnetoelastic coupling and spin contributions to entropy and thermal transport in biferroic yttrium orthochromite.

Direct engineering of material properties through exploitation of spin, phonon, and charge-coupled degrees of freedom is an active area of development in materials science. However, the relative contribution of the competing orders to controlling the desired behavior is challenging to decipher. In particular, the independent role of phonons, magnons, and electrons, quasiparticle coupling, and relative contributions to the phase transition free energy largely remain unexplored, especially for magnetic phase transitions.

High-Temperature Thermal Cycling Effect on the Irreversible Responses of Lattice Structure, Magnetic Properties, and Electrical Conductivity in CoFeO Spinel Oxide.

We report high-temperature synchrotron X-ray diffraction (SXRD), magnetization, and current-voltage (-) characteristics for the samples of CoFeO ferrite. The material was prepared by chemical reaction of the Fe and Co nitrate solutions at pH ∼ 11 and subsequent thermal annealing. Physical properties of the samples were measured by cycling the temperature from 300 K to high temperature (warming mode) and returning back to 300 K (cooling mode).