Complex materials with many components are used in the manufacturing process of some of today's most advanced technology tools. However, the properties of these materials could change under specific pressures, temperatures and magnetic fields.
Researchers from the Collaborative Innovation Center of Advanced Microstructures in Nanjing, China, Fudan University, LSU and the University of Florida conducted research on materials that separate into different regions through a process called electronic phase separation. Up to date, this process was poorly understood.
Their research advances the understanding of these materials and can lead to new ways of manipulating without having to apply an external magnetic field, change their chemical concentration, or discover new materials. Their research paper was recently published in the Proceedings of the National Academy of Sciences.
The researchers manipulated a steel grey mineral called manganite, usually used to produce magnetic hard discs for computers. They created holes called antidotes in thin films of manganite. Their research found that the edges of the antidotes were magnetic.
According to LSU Physics Professor Ward Plummer, a co-author on the study, the discovery of the magnetic edge suggests the idea that the antidote could make this work possible. This discovery opens new possibilities in creating advanced tech tools and no one has ever seen this before.
According to the research team, the magnetic phase state at the edges of the antidots has raised the phase transition temperature of the manganite film in the metal-to-insulators. This phenomenon was replicated by the researchers through simulations.
Jian Shen, head of the Department of Physics at Fudan University and a co-author on the paper, said that scientists have tried before to reduce the operating field and increase the temperature or tried to change the chemical composition or the substrate. But with the new approach, all will become much easier. Plummer added that when the temperature gets above room temperature it is possible to switch the material by using a magnetic field.
According to scientists, electronic phase separation (EPS) is among the most intriguing properties of complex materials. Up to date, scientists have made great efforts to understand and manipulate EPS, but it's still a mystery how their phases are created and grow during percolation, as well as the artificial fabrication and control process of these phases is little understood.
The new research has opened the possibility to tune the physical proprieties of the system without changing doping concentration or using external fields. By fabricating antidotes in maganites and using their ferromagnetic metallic edge state, it is possible to control the growth and nucleation of EPS domains.
