Methods of forming spinel ferrite nanoparticles containing a chromium-substituted copper ferrite as well as properties (e.g. particle size, crystallite size, pore size, surface area) of these spinel ferrite nanoparticles are described. Methods of preventing or reducing microbe growth on a surface by applying these spinel ferrite nanoparticles onto the surface in the form of a suspension or an antimicrobial product are also described.

Provided are a copper-chromium oxide spinel, and a resin composition and a resin molded article containing the copper-chromium oxide spinel. Specifically, provided is a copper-chromium oxide spinel with a particle size distribution spread SPAN=(D90D10)/D50 of 2 or less where, in volume-converted particle size distribution obtained by a laser diffraction and scattering method, particle sizes with a cumulative frequency from a smaller particle size side of 10%, 50%, and 90% are D10, D50, and D90, respectively.

The invention relates to a class of electrochemical energy storage materials and a preparation method and application thereof. A porous metal oxide-based electrochemical energy storage material at least comprises a host metal oxide with a hierarchical pore structure; wherein, the host metal oxide is a single crystal, quasicrystal, or twin crystal structure with ordered atomic lattice arrangement, the crystal is rich in oxygen atom vacancy defects, the structural general formula is M.sub.xO.sub.y-z, wherein M is selected from one or more combinations of niobium element, molybdenum element, titanium element, vanadium element, manganese element, iron element, cobalt element, nickel element, copper element, zinc element, tungsten element, tantalum element, and zirconium element; and 1x2, 1y5, and 0.1z0.9, preferably Nb.sub.2O.sub.5-z.

A composition MxABO.sub.4 can include: a composition ABO.sub.4, wherein M is selected from the group consisting of: Ca, Mg, and Na, wherein M is intercalated with ABO.sub.4, wherein x is greater than or equal to 0, wherein A includes at least one selected from the group consisting of: Dy, Er, Sm, Nd, Tm, Pr, Gd, Sc, Y, Eu, Ho, Tb, Bi, Lu, La, Yb, Ce, Zr, Hf, Th, U, Ce, In, Tl, Pa, Pu, Ba, Pb, and Sr, wherein B includes at least one selected from the group consisting of: B, P, V, Cr, As, Si, Ge, N, Nb, Mo, Ru, Sb, W, Re, Bi, Mn, Fe, Se, Tc, Sn, and Co, and wherein the composition ABO.sub.4 has a tetragonal structure.

A conductive paste included in inner electrodes of a multilayer ceramic capacitor is fired and includes a conductive metal powder, a ceramic powder, an organic solvent, and an organic binder. The conductive metal powder includes copper, and at least a portion of the ceramic powder is a powder of at least one oxide of an ABO.sub.3 type with a specified ionic radius in which a ratio of a six-coordinate ionic radius of an A-site element in ABO.sub.3 to a six-coordinate ionic radius of copper is about 0.96 or greater and about 1.04 or less.

A conductive paste included in inner electrodes of a multilayer ceramic capacitor is fired and includes a conductive metal powder, a ceramic powder, an organic solvent, and an organic binder. The conductive metal powder includes copper, and at least a portion of the ceramic powder is a powder of at least one oxide of an ABO.sub.3 type with a specified ionic radius in which a ratio of a six-coordinate ionic radius of an A-site element in ABO.sub.3 to a six-coordinate ionic radius of copper is about 0.96 or greater and about 1.04 or less.