A radio wave absorber includes a base member, and a radio wave absorption film formed on the base member. The radio wave absorption film includes at least MTC-substituted ε-Fe.sub.2O.sub.3 and black titanium oxide. The MTC-substituted ε-Fe.sub.2O.sub.3 is a crystal belonging to the same space group as an ε-Fe.sub.2O.sub.3 crystal and expressed by ε-M.sub.xTi.sub.yCo.sub.yFe.sub.2−2y−xO.sub.3 where M is at least one element selected from the group consisting of Ga, In, Al, and Rh, 0<x<1, and 0<y<1.

The invention relates to active electrode materials and to methods for the manufacture of active electrode materials. Such materials are of interest as active electrode materials in lithium-ion or sodium-ion batteries. The invention provides an active electrode material expressed by the general formula [M1].sub.x[M2].sub.(1−x)[Nb]y[O].sub.z, wherein: M1 and M2 are different; M1 represents one or more of Ti, Mg, V, Cr, W, Zr, Mo, Cu, Fe, Ga, Ge, Ca, K, Ni, Co, Al, Sn, Mn, Ce, Te, Se, Si, Sb, Y, La, Hf, Ta, Re, Zn, In, or Cd; M2 represents one or more of Mg, V, Cr, W, Zr, Mo, Cu, Ga, Ge, Ca, K, Ni, Co, Al, Sn, Mn, Ce, Sb, Y, La, Hf, Ta, Zn, In, or Cd; and wherein x satisfies 0<x<0.5; y satisfies 0.5≤y≤49 z satisfies 4≤z≤124.

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.

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 LiMO2, 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.

An iron oxide powder includes a porous structure having the diameter of from 0.3 μm to 2 μm, wherein the iron oxide powder has an aluminum content of from 10 mol % to 80 mol %.

Aluminium-containing iron oxide pigments of the formula Fe.sub.2-xAl.sub.xO.sub.3 with x values from 0.01 to 0.25, characterized in that they possess an a* value of 30.5 to 32.5 CIELAB units and a b* value of 25.5 to 30.5 CIELAB units, measured in each case as full shade in the alkyd resin according to DIN EN ISO 787-25:2007.

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+δ 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, 0≤x≤0.2, 0≤y≤0.2, and 0≤z≤0.2 are satisfied, and δ is a value securing electrical neutrality.

A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing an oxygen carrier having oxygen ionic conductivity, and a basic oxide supported on the oxygen carrier. In addition, the basic oxide preferably contains at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), cobalt (Co), strontium (Sr), and rubidium (Rb). The reducing agent has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

Provided is an electrochemical element having excellent load characteristics and charge-discharge cycle characteristics, an electrode active material that can constitute the electrochemical element, a method for manufacturing the electrode active material, an electrode material, an electrode, and a movable body including the electrochemical element. The electrode active material for an electrochemical element according to the present invention includes an oxide that has a monoclinic crystal structure and satisfies the following general formula (1): A.sub.yM.sup.1.sub.αAl.sub.x−αNb.sub.12−x−zM.sup.2.sub.zO.sub.29−δ (1). In the general formula (1), A is at least one element selected from Li and Na, M1 is at least one element selected from the group consisting of Fe, Mn, Zn Cu, Ag, Mg Ca, Sr, Ba, Co, Eu, Y, Bi, La, Ce, Nd, Sm, and Gd, M2 is specific element, awl x, y, z, δ, and α satisfy 0<x≤1.1, 0≤y≤24, 0≤z≤2, −1≤δ≤2, and 0<α≤0.4x.

The present invention provides an electrocatalytic material and a method for making an electrocatalytic material. There is also provided an electrocatalytic material comprising amorphous metal or mixed metal oxides. There is also provided methods of forming an electrocatalyst, comprising an amorphous metal oxide film.