NIST researchers highlights challenges of "talking ceramics"

In the last three decades, communications technologies have been completely transformed by the "wireless revolution." Devices such as cell phones are now so common that many consumers are forgoing the hardwired versions altogether. This remarkable technological explosion could not have taken place without several key historical events, such as Marconi's first wireless transmission across the Atlantic Ocean in 1901, and the discovery of the transistor almost 50 years later.

Critical to the proliferation of microwave communications was the discovery of a small number of ceramic materials with special properties permitting them to be used as dielectric resonators and filters, thereby enabling them to function as "talking ceramics." Although the theoretical possibilities and potential applications of dielectric resonators were recognized in 1939, it was not until the 1970s that ceramics with the required dielectric properties were discovered by researchers at NIST and a private company. The construction of commercially viable cellular base stations resulted directly from that work. In the ensuing two decades, wireless applications proliferated while the size and weight of user devices plummeted.

Today, dielectric ceramics are critical ingredients of resonators, filters, and other key components supporting the $40 billion wireless communication industry. The success of this technology has created an unending demand for better materials, as described by NIST staff in "Talking Ceramics," an invited article published in the Nov. 8, 2002, issue of Science. New microwave ceramics, the article explains, are needed to accommodate an increasingly crowded communications spectrum and improve device and base station capabilities, while limiting or reducing manufacturing costs. This situation presents a considerable challenge to materials scientists because designing materials with the desired properties requires an understanding that is not yet currently available.

NIST is responding to this challenge by its aggressive pursuit of research on the phase equilibria and dielectric properties of these important ceramics. The Science article describes several recent accomplishments by NIST materials scientists and others that are helping to place the search for new dielectric ceramics on a more solid theoretical foundation. In addition, promising, but still exploratory approaches to designing and fabricating new types of dielectric materials are noted.

The full text of the article can be found at www.ceramics.nist.gov. The article also was the focus of a feature story that appeared in The New York Times on Nov. 28, 2002, and of a NIST news release that can be found at www.nist.gov/public_affairs/releases/n02-22.htm.

CONTACT: Terrell Vanderah, [phone]; [email protected].