IDAHO FALLS, Idaho — Filled with pits, seams and fissures, the images that Darin J. Tallman examined in a secure laboratory here looked like the surface of Mars. But they were extreme magnifications of slivers of an odd new material — half metal, half ceramic — that tolerates high heat with ease, and that several companies hope might form the basis of a new reactor technology.

Mr. Tallman’s experiments are among many being conducted here outside Idaho Falls, in the high desert, far from population centers, in search of something that will drive the nuclear industry into its next incarnation.

The industry has been in a slump. Old plants are unprofitable in the United States. In Germany, they are seen as an unacceptable safety hazard; their future in Japan is uncertain. Research has been in a slump, too.

But many experts, as well as investors, say that for the world to meet rising demand for electricity and simultaneously reduce carbon emissions, nuclear power will have to be part of the mix.