A multi-step method to produce materials, and coatings of materials, which has three key characteristics. The first is that the density of the resulting materials or coatings can be controllably and widely variable from less than ten percent of normal density up to normal density. The second key characteristic of the invention is the use of starting materials having powders that have grains (particles) with one, two or three dimensions on the size scales of nanometers or micrometers. The third major characteristic part of the invention is the use of microwave radiation or induction heating to quickly raise the temperature of the powders to produce materials or coatings before deleterious diffusion and densification can occur. These features produce new types of materials with properties favorable to many applications, such as chemical and other catalysis, electrolysis in batteries and fuel cells, and light weight structural components.