Would you rather have data storage that is compact or reliable? Both, of course! Digital electronic devices like hard drives rely on magnetic memory to store data, encoding information as “0”s and “1”s that correspond to the direction of the magnetic moment, or spin, of atoms in individual bits of material. For magnetic memory to work, the magnetization should not change until the data is erased or rewritten. Unfortunately, some magnetic materials that are promising for high density storage have low data stability, which can be improved by squeezing or stretching the crystal structures of magnetic memory materials, enhancing a material property called magnetic anisotropy.
You may know that the media used in magnetic recording technologies, such as computer hard drives, are made of millions of tiny nanomagnets. Each nanomagnet can be switched up or down to record bits of information as ones and zeros. These media are constantly subjected to magnetic fields in order to write, read, and erase information. If you have ever placed a magnet too close to your laptop or cell phone, you know that exposure to an external magnetic field can disrupt information stored this way. Did you know that it is possible for the nanomagnets to "remember" their previous state, if carefully manipulated under specific magnetic field and temperature conditions? Using a kind of memory called topological magnetic memory, scientists have found out how to imprint memory into magnetic thin films by cooling the material under the right conditions.