{"id":590,"date":"2015-08-11T00:24:57","date_gmt":"2015-08-11T00:24:57","guid":{"rendered":"http:\/\/www.kurzweilai.net\/?p=259273"},"modified":"2015-08-12T04:11:57","modified_gmt":"2015-08-12T04:11:57","slug":"new-solid-state-memory-technology-allows-for-highest-density-non-volatile-storage","status":"publish","type":"post","link":"https:\/\/hoo.central12.com\/fugic\/2015\/08\/11\/new-solid-state-memory-technology-allows-for-highest-density-non-volatile-storage\/","title":{"rendered":"New solid-state memory technology allows for highest-density non-volatile storage"},"content":{"rendered":"
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A schematic shows the layered structure of new type of solid-state memory developed at Rice University (credit: Tour Group\/Rice University)<\/p><\/div>\n

Scientists in the\u00a0Rice University<\/a> lab of chemist James Tour have created a solid-state memory technology that allows for high-density 162 gigabits nonvolatile storage, much higher than other oxide-based memory systems under investigation by scientists. (Eight bits equal one byte; a 162-gigabit unit would store about 20 gigabytes of information.)<\/p>\n

Applying voltage to a 250-nanometer-thick sandwich of graphene<\/a>, tantalum<\/a>, nanoporous tantalum oxide<\/a> (an insulator), and platinum creates addressable bits where the layers meet. Control voltages shift oxygen ions and vacancies to switch the bits between ones and zeroes.<\/p>\n

Like the Tour lab\u2019s previous discovery of\u00a0silicon oxide memories<\/a>, the new devices require only two electrodes per circuit, making them simpler than present-day flash memories, which use three. \u201cThis is a new way to make ultradense, nonvolatile computer memory,\u201d Tour said.<\/p>\n

Nonvolatile random-access memories, such as such as flash memory in smartphones and tablets, hold their data even when the power is off, unlike volatile random-access computer memories (in most computers), which lose their contents when the machine is shut down.<\/p>\n

Modern memory chips have many requirements: They have to read and write data at high speed and hold as much as possible. They must also be durable and show good retention of that data while using minimal power. These are provided by Rice\u2019s new design, which requires only one hundredth the amount of energy required with present devices, Tour says.<\/p>\n

\u201cThis tantalum memory is based on two-terminal systems, so it\u2019s all set for 3-D memory stacks,\u201d he said. \u201cAnd it doesn\u2019t even need diodes or selectors, making it one of the easiest ultradense memories to construct. This will be a real competitor for the growing memory demands in high-definition video storage and server arrays.\u201d<\/p>\n

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A layered structure of tantalum, tantalum oxide, multilayer graphene, and platinum is the basis for a new type of nonvolatile memory (credit: Tour Group\/Rice University)<\/p><\/div>\n

In making the material, the researchers found the tantalum oxide gradually loses oxygen ions, changing from an oxygen-rich, nanoporous semiconductor at the top to oxygen-poor at the bottom. Where the oxygen disappears completely, it becomes pure\u00a0tantalum, a metal. The graphene does double duty as a barrier that keeps platinum from migrating into the tantalum oxide and causing a short circuit.*<\/p>\n