The invention is directed to hydrophilic and hydrophobic superparamagnetic nanoparticles and their use as contrast agents for NMR including agents that distinguish oil and water in NMR logging of geological formations containing oil or water. Methods of making these SPIONs are also described.

The present invention provides iron oxide magnetic particles including an iron oxide and MX.sub.n, wherein M includes one or more selected from the group consisting of Cu, Sn, Pb, Mn, Ir, Pt, Rh, Re, Ag, Au, Pd, and Os, X includes one or more selected from the group consisting of F, Cl, Br, and I, and n is an integer of 1 to 6.

The invention relates to heterostructures including a layer of a two-dimensional material placed on a multiferroic layer. An ordered array of differing polarization domains in the multiferroic layer produces corresponding domains having differing properties in the two-dimensional material. When the multiferroic layer is ferroelectric, the ferroelectric polarization domains in the layer produce local electric fields that penetrate the two-dimensional material. The local electric fields can influence properties of the two-dimensional material, including carrier density, transport properties, optical properties, surface chemistry, piezoelectric-induced strain, magnetic properties, and interlayer spacing. Methods for producing the heterostructures are provided. Devices incorporating the heterostructures are also provided, including tunable sensors, optical emitters, and programmable logic gates.

Disclosed herein are monodisperse superparamagnetic beads, having a core-shell structure, and a method for preparing the beads.

A method of manufacturing a magnetic wire example includes depositing a magnetic film, which has a composition that enables measuring motion of a magnetic domain wall in the magnetic film, on/above a silicon substrate, forming the magnetic film on the silicon substrate on which the magnetic film is deposited using a wire pattern and an electrode pattern of a certain specification, shielding a central part of the magnetic wire in a photolithography method by an edge milling pattern which corresponds to a predetermined specification, and ablating an edge portion of the magnetic wire which is not shielded by an ion milling.

The disclosed technology provides a cladded permanent magnet comprising: a core magnet region containing a core magnetic material; and a magnet cladding containing a shell magnetic material comprising (i) a magnetic compound that is chemically the same as the core magnetic material, (ii) one or more rare earth elements, and (iii) metal-containing inoculant nanoparticles, wherein the magnet cladding is disposed on the core magnet region, wherein the magnet cladding has at least 10% higher ambient-temperature magnetic coercivity compared to the core magnet region. The cladded permanent magnet is made via high-throughput laser-based additive manufacturing to optimize the architecture of NdFeB or other magnets, generating site-specific, demagnetization-resistant microstructures. This disclosure teaches a rapid, single-step laser-based process to tailor the easy axis alignment, grain size, and microstructure of a permanent magnet at corners and edges to resist demagnetization.

Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include α″-Fe.sub.16N.sub.2 phase domains; wherein a ratio of integrated intensities of an α″-Fe.sub.16N.sub.2 (004) x-ray diffraction peak to an α″-α″-Fe.sub.16N.sub.2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.

A method of making a magnetically-drivable microrobot that is suitable for carrying and delivering cells includes photo-curing a photo-curable material composition to form a body of the magnetically-drivable microrobot. The photo-curable material composition includes a degradable component, a structural component, a magnetic component, and a photo-curing facilitation composition including a photoinitiator component and a photosensitizer component.

A manufacturing method of a sintered magnet is described. The method includes forming a pre-sintering body from a first magnetic powder and a second magnetic powder (containing a heavy rare earth element, HRE) so that at least part of the second magnetic powder is provided at at least one inner portion of the pre-sintering body and surrounded format least two opposite sides by the first magnetic powder; sintering the pre-sintering body; and annealing the sintered pre-sintering body at an annealing temperature lower than the sintering temperature, thereby causing inter-grain diffusion of HRE from the HRE reservoir zone to the grain boundary phase. After the annealing, the grain boundary phase contains the HRE in a higher concentration than the main phase.

Provided is a powder of a β-iron oxyhydroxide-based compound that is a group of particles of a β-iron oxyhydroxide-based compound represented by Formula (1) below; in which a surface of the particles of the β-iron oxyhydroxide-based compound is modified with a surface modifier; in which, in a case where the powder is dispersed in water to be made into a sol, a zeta potential of the powder is equal to or higher than +5 mV at pH 10; and
β-A.sub.aFe.sub.1-aOOH  (1)
in which, in Formula (1), A represents at least one metallic element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.