A team of researchers led by professor Hideo Hosono of the Tokyo Institute of Technology has developed a new type of alumina cement that conducts electricity like metal by altering the crystal structure at the nano level.
Ordinary alumina cement made from a lime-alumina compound (C12A7) has a crystal structure consisting of asymmetric cages, making it a poor conductor of electricity. But by sealing the alumina cement compound along with titanium inside a glass tube and heating it to 1,100 degrees Celsius, the researchers were able to create a homogenized, symmetrical cage structure that conducts electricity like metal.
Results indicate the cement's electrical conductivity is on par with that of manganese at room temperature. Moreover, like other metals, the cement's conductivity increases as its temperature decreases.
The researchers say that forming the cement into thin membranes would make it nearly transparent, making it an ideal substitute material for rare metals such as indium, which is used in plasma and liquid-crystal displays. In addition to being cheaper than rare metals, the cement would make an environmentally-friendly alternative because its ingredients are more readily available.
The Tokyo Institute of Technology worked with researchers from Osaka Prefecture University, the Institute of Physical and Chemical Research (RIKEN), and the Japan Synchrotron Radiation Research Institute (SPring-8) to develop the cement. The results are published in the April 11 edition of Nano Letters.