Composite material, composite material substrate, composite material dispersed fluid, and manufacturing methods thereof

A method of manufacturing a composite material comprising:

• generating an aggregate precursor out of a solution containing a first metal salt and a second metal salt by:
• generating second metal compound particulates under presence of a pH adjuster, and
• depositing a first metal particle by a reducing action of the second metal compound particulates, such that the first metal particle derived from the first metal salt is surrounded by the second metal compound particulates derived from the second metal salt,
• wherein the first metal salt is a salt of a metal having an ionization tendency equal to or lower than an ionization tendency of Zn, and
• wherein the second metal salt is a salt of at least one metal selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Zr, Fe, Ti, Al, Mg, Co, Ni, Mn, Cr, Mo, W, and V;
• and
• obtaining a composite material by calcinating the generated aggregate precursor, the composite material comprising an aggregate that contains:
• the first metal particle constituting a core and having an average primary particle diameter ranging from 10 to 400 nm, and
• second metal oxide particulates directly contacting an outer surface of the first metal particle and having an average primary particle diameter ranging from 1 to 100 nm.