What is a phase change material?A phase change material (PCM) is a substance that changes from one state of matter to another at a certain temperature. It can be compared to water; when boiled (at 100 °C ) it turns to a gas and when frozen (at 0 °C)turns to ice.
PCMs are usually used in construction as a means of regulating room temperature. When the temperature in a room gets high, the PCM liquefy and absorb and store heat. Once the temperature lowers, it solidifies and releases the absorbed heat.
PCMs usually utilize the solid to liquid phase change because a phase change to gas requires a larger volume or high pressure to store the material in that state.
Current phase change materials use paraffin as its prime material. Paraffin (a wax) melts at a specified temperature and solidifies back again at a lower temperature. These are produced as microscopic wax spheres (paraffin wrapped in a glass acrylic containers called beads) integrated into building materials.
Penn researchers' study of phase change materials could lead to better computer memory
Memory devices for computers require a large collection of components that can switch between two states, which represent the 1's and 0's of binary language. Engineers hope to make next-generation chips with materials that distinguish between these states by physically rearranging their atoms into different phases. Researchers at the University of Pennsylvania have now provided new insight into how this phase change happens, which could help engineers make memory storage devices faster and more efficient.
The research was conducted by Ritesh Agarwal, associate professor in the Department of Materials Science and Engineering in Penn's School of Engineering and Applied Science, along with members of his research group. A.T. Charlie Johnson, professor in the Department of Physics and Astronomy in the School of Arts and Sciences, and Ju Li, now a professor of nuclear science and engineering at the Massachusetts Institute of Technology, also contributed to the study.
Their research was published in the journal Science.
