Studied for more than a century, ferroelectric materials exhibit a spontaneous polarization in one or more directions along a crystal axis. Thermodynamically stable, the polarized states can be switched from one to the other by applying an electric field that exceeds what’s known as the coercive field Ec. That switchability provides the basis for the nonvolatile RAMs in computing. (See the article by Orlando Auciello, James F. Scott, and Ramamoorthy Ramesh, Physics Today, July 1998, page 22.)

Since the 1960s, electrical engineers have been designing memory elements based on conventional ferroelectrics such as the perovskite barium titanate. But manufacture is complicated by the challenge of integrating those materials with silicon-based semiconductors. What’s more, the memory elements are difficult to scale down to atomic dimensions for energy efficiency. Between 2019 and 2021, researchers discovered that crystalline films of alloyed aluminum nitride are ferroelectrics that could solve both...

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