An oxide ion conductor has a X.sub.3Z.sub.2(TO.sub.4).sub.3 structure, where X is a divalent metal element, Z is a trivalent metal element, and T is a tetravalent metal element, and has a composition expressed by (X.sub.1-xA.sub.x).sub.3(Z.sub.1-yB.sub.y).sub.2(T.sub.1-zC.sub.z).sub.3O.sub.12+ where the element X is Ca, Fe, Gd, Ba, Sr, Mn, and/or Mg, the element Z is Al, Cr, Fe, Mn, V, Ga, Co, Ni, Ru, Rh, and/or Ir, the element T is Si and/or Ge, an element A is La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and/or Sr, an element B is Zn, Mn, Co, Ru, and/or Rh, and an element C is Si, Al, Ga, and/or Sn, 0x0.2, 0y0.2, and 0z0.2 are satisfied, and is a value securing electrical neutrality.

There is provided a magnetic material that has an excellent electromagnetic wave absorption performance in a wide frequency range even under low temperature and high temperature environments and that ensures the absorption performance, and provided a magnetic material as a mixture of a magnetic material having positive slope of change in coercive force dependent on temperature, and a magnetic material having negative slope of change in coercive force dependent on temperature.

Methods to fabricate tightly packed arrays of nanoparticles are disclosed, without relying on organic ligands or a substrate. In some variations, a method of assembling particles into an array comprises dispersing particles in a liquid solution; introducing a triggerable pH-control substance capable of generating an acid or a base; and triggering the pH-control substance to generate an acid or a base within the liquid solution, thereby titrating the pH. During pH titration, the particle-surface charge magnitude is reduced, causing the particles to assemble into a particle array. Other variations provide a device for assembling particles into particle arrays, comprising a droplet-generating microfluidic region; a first-fluid inlet port; a second-fluid inlet port; a reaction microfluidic region, disposed in fluid communication with the droplet-generating microfluidic region; and a trigger source configured to trigger generation of an acid or a base from at least one pH-control substance contained within the reaction microfluidic region.

To provide magnetoplumbite-type hexagonal ferrite particles represented by Formula (1) and having a single crystal phase, and the application. In Formula (1), A represents at least one metal element selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.5x8.0.

AFe.sub.(12-x)Al.sub.xO.sub.19Formula (1)

Sintering is an important issue in creating crystalline metal oxides with high porosity and surface area, especially in the case of high-temperature materials such as metal aluminates. Herein we report a rationally designed synthesis of metal aluminates that diminishes the surface area loss due to sintering. Metal aluminate (e.g. MeAl.sub.2O.sub.4or MeAlO.sub.3Me=Mg, Mn, Fe, Ni, Co, Cu, La, or Ce; or mixture thereof) supported on -Al.sub.2O.sub.3 with ultralarge mesopores (up to 30 nm) was synthesized through microwave-assisted peptization of boehmite nanoparticles and their self-assembly in the presence of a triblock copolymer (Pluronic P123) and metal nitrates, followed by co-condensation and thermal treatment. The resulting materials showed the surface area up to about 410 m.sup.2.Math.g.sup.1, porosity up to about 2.5 cm.sup.3.Math.g.sup.1, and very good thermal stability. The observed enhancement in their thermomechanical resistance is associated with the faster formation of the metal aluminate phases. The nanometer scale path diffusion and highly defective interface of -alumina facilitate the counter diffusion of Me.sup.X+ and Al.sup.3+ species and further formation of the metal aluminate phase.

A composite metal oxide material and a preparation method thereof, a positive electrode plate, a secondary battery, a battery module, a battery pack and an electrical device are provided. The composite metal oxide material includes a central core and a coating layer on the surface of the central core, in which the central core material has a chemical formula of Li.sub.5Fe.sub.xM.sub.1-xO.sub.4, 0.6?x?1; the coating layer material has a chemical formula of LiMO.sub.2, M is one or more metal elements with +3 valence, and the absolute value of the difference between the +3-valence ion radius of Fe and the +3-valence ion radius of M is ?0.02 nm. The composite metal oxide material of the present disclosure makes the secondary battery have high charge capacity, high discharge capacity and long cycle life.

Provided are a magnetic recording medium including: a non-magnetic support; and a magnetic layer which is provided on at least one surface of the non-magnetic support and includes particles of epsilon type iron oxide-based compound, and a binding agent, in which a contact angle measured regarding a surface of the magnetic layer is equal to or greater than 30.0 and smaller than 45.0 with respect to 1-bromonaphthalene and 80.0 to 95.0 with respect to water, a manufacturing method of particles of an epsilon iron oxide-based compound, and a manufacturing method of a magnetic recording medium.

There is provided a magnetic substance containing substituted -iron oxide particles applicable as a magnetic toner of one-component development system, and a technique related thereto, which is the magnetic substance containing substituted -iron oxide particles in which a part of -iron oxide is substituted with a metal element other than iron, and satisfying at least one of the following conditions: (Condition 1) A molar extinction coefficient of a magnetic substance dispersion liquid at a wavelength of 450 nm is less than 770 dm.sup.3 mol.sup.1 cm.sup.1. (Condition 2) A molar extinction coefficient of the magnetic substance dispersion liquid at a wavelength of 500 nm is less than 430 dm.sup.3 mol.sup.1 cm.sup.1.

Methods to fabricate tightly packed arrays of nanoparticles are disclosed, without relying on organic ligands or a substrate. In some variations, a method of assembling particles into an array comprises dispersing particles in a liquid solution; introducing a triggerable pH-control substance capable of generating an acid or a base; and triggering the pH-control substance to generate an acid or a base within the liquid solution, thereby titrating the pH. During pH titration, the particle-surface charge magnitude is reduced, causing the particles to assemble into a particle array. Other variations provide a device for assembling particles into particle arrays, comprising a droplet-generating microfluidic region; a first-fluid inlet port; a second-fluid inlet port; a reaction microfluidic region, disposed in fluid communication with the droplet-generating microfluidic region; and a trigger source configured to trigger generation of an acid or a base from at least one pH-control substance contained within the reaction microfluidic region.

Magnetic powder includes: at least one epsilon-phase iron oxide-based compound selected from the group consisting of -Fe.sub.2O.sub.3 and a compound represented by Formula (1); and a surface treatment layer including a silane compound on at least a part of a surface. The magnetic powder has an average particle diameter of 8 nm to 20 nm. The content ratio of carbon atoms of the silane compound included in the surface treatment layer to iron atoms of the at least one epsilon-phase iron oxide-based compound selected from the group consisting of -Fe.sub.2O.sub.3 and the compound represented by Formula (1) is 0.05% to 0.5% in terms of the number of atoms. A manufacturing method thereof and applications thereof are also provided. In Formula (1), A represents at least one metal element other than Fe and a represents a number that satisfies a relationship of 0<a<2.

-A.sub.aFe.sub.2-aO.sub.3(1)