Effect of 10 MeV iodine ion irradiation on the magnetic properties and lattice structure of CeO2

• Published in: Japanese Journal of Applied Physics Vol. 53; no. 5S1
• Main Authors: Kishino, Takanori, Shinoda, Ryoichi, Shimizu, Koki, Saitoh, Yuichi, Ishikawa, Norito, Okamoto, Yoshihiro, Hori, Fuminobu, Matsui, Toshiyuki, Iwase, Akihiro
• Format: Journal Article
• Language: English
• Published: The Japan Society of Applied Physics 22.04.2014
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.53.05FC07

We have studied the magnetic properties and the lattice structure of pure CeO2 irradiated with swift heavy ions. Experimental results showed that the ferromagnetism was induced at room temperature by 10 MeV I ion irradiation. The value of saturation magnetization increases with increasing the ion fluence and reaches a maximum value at about the fluence of 1.2 × 1013/cm2, and then decreases. The X-ray diffraction (XRD) spectra showed that the lattice parameter of CeO2 increases with increasing ion fluence. To examine the origin of the ferromagnetic state in CeO2, we compared the result for 10 MeV I ion irradiation with that for 200 MeV Xe ion irradiation. We also estimated the magnetic properties for CeO2 pellets annealed at 1273 K in a vacuum. From the experimental results, we concluded that oxygen vacancies, which are produced by electronic excitation process due to high energy ion beam, play an important role in the appearance of the ferromagnetic state in CeO2.