Nanotechnology: An oxide with a shape memory

An oxide material with a shape memory at the nanoscale is presented in Nature Communications this week. The material, bismuth ferrite, can hold an exceptionally large strain without being damaged and shows superior performance to conventional shape memory materials. As bismuth ferrite can easily be integrated into microelectronics, this opens interesting new perspectives for applications of this material.

The properties of bismuth ferrite have made the material a promising candidate for various electronic applications. Jinxing Zhang and colleagues add yet another interesting feature to the material’s portfolio: a shape memory effect at the nanoscale. After being deformed at cold temperature, the oxide remembers its original shape when it is heated or stimulated with an electric field. Conventionally, nickel alloys are used in shape memory applications (for example as expandables in blood vessel surgery for surgery), but these materials suffer from a number of problems, such as surface effects, especially at the nanoscale. Bismuth ferrite has now been shown to be a good alternative to those alloys, especially because it has an exceptional performance. This performance is usually measured by the strain that a material can hold upon deformation without being permanently damaged. Zhang and co-authors show that the maximum recoverable strain in bismuth ferrite reaches 14%.