Researchers from North Carolina State University and the Georgia Institute
of Technology have demonstrated a less-expensive way to create textured nickel ferrite
(NFO) ceramic thin films, which can easily be scaled up to address
manufacturing needs. NFO is a magnetic material that holds promise for
microwave technologies and next-generation memory devices.
Specifically, this is the first time researchers have used a chemical
deposition process to create NFO thin films that are “textured”—meaning they
have an aligned crystalline structure. Arraying the crystalline structure in an
orderly fashion is important because it maximizes the magnetic properties of
Using a chemical deposition process also makes it easier to modify, or “dope,” the NFO by adding additional materials, such as zinc. By doping the
NFO, researchers can optimize the material for various applications. For
example, adding zinc allows the NFO to retain its magnetic properties at higher
The technique used to create the NFO thin films begins by introducing nickel
and iron compounds into an organic solvent to create an NFO solution. The
solution is then injected onto a silicon wafer that has been coated with
platinum. The wafer is then spun, spreading the solution uniformly across the
wafer’s surface. The wafer is heated to evaporate the solvent, then heated
again to 750 C to crystallize the NFO.
“This approach can be used to deposit textured NFO thin films over areas at
least as large as 10 centimeters by 10 cm,” says Justin Schwartz, co-author of
the paper, Kobe Steel Distinguished Professor and Department Head of the
Materials Science and Engineering Department at NC State. Previous efforts to
create textured NFO thin films have relied on techniques that can only deposit
such thin films over a small area.
The paper was published in the Journal of Applied Physics.
Source: North Carolina State University