Magnetic Microstructure of Fe 3 - x Al x O 4 Superparamagnetic Magnetites

We have studied superparamagnetic magnetites with various isomorphous aluminum contents, identified the cation distribution in their structure, and demonstrated nonlinear variations in their unit cell parameter and density and also a nonlinear variation in their magnetization, with a maximum at an aluminum content of 3.6% (x = 0.3). The conclusion has been made that the properties of the superparamagnetic magnetites with isomorphous aluminum can be used in optimizing the composition of nanocomposite materials with tailored magnetic properties.