Researchers at the University of Southern California say they've
developed a memristor memory device that
continued operating at 700 degrees Celsius. "And crucially, 700 degrees was not the limit, it was simply as hot as their testing equipment could go," adds ScienceAlert. "The device showed no signs of failing." From the report: The device is called a memristor and it's a nanoscale component that can both store information and perform computing operations. Think of it as a tiny sandwich with two electrode layers on the outside and a thin ceramic filling in the middle. The team built theirs from tungsten, the metal with the highest melting point of any element, combined with a ceramic called hafnium oxide, and with a layer of graphene at the bottom. Each material can withstand enormous heat. Together, they turned out to be extraordinary.
What makes graphene the key ingredient is the way it interacts with tungsten at the atomic level. In a conventional device, heat causes metal atoms to drift slowly through the ceramic layer until they bridge the two electrodes, short circuiting everything and leaving the device permanently broken. Graphene stops that process dead. Its surface chemistry with tungsten is ... almost like oil and water. Tungsten atoms that drift toward the graphene find they simply cannot take hold, no anchor, no short circuit, no failure. The team used advanced electron microscopy and quantum level computer simulations to understand exactly why, turning a single lucky result into a repeatable principle. The findings have been published in the journal Science.
