Tailoring of defects dependent magnetic properties of swift heavy ion irradiated CeO2 for spintronics application

Abstract

The present investigation reports the swift heavy ion induced effects on cerium oxide (CeO2) thin films. These thin films were deposited on Si (111) substrates by the electron-beam evaporation method and irradiated by a 100 MeV O7+ ion beam with different ion fluences. X-ray diffraction analysis of these films confirms the stable fluorite phase of CeO2 even after the higher fluence of irradiations. Raman measurement also supports the presence of the F2g phase of CeO2 and the presence of defect states. The Gaussian deconvolution of photoluminescence (PL) spectra reveals various defect-associated peaks. The broad peaks in the PL spectra are associated with oxygen vacancies and are red-shifted (494–520 nm) with ion fluences. The surface morphological images show the modification in the surface roughness with ion irradiation and the re-growth of smaller circular-formed nanoparticles on the surface is observed at the fluence of 5 × 1011 ions/cm2. Magnetic measurements show an enhancement in magnetic ordering with ion irradiation. All the samples demonstrate room temperature ferromagnetism with magnetic saturation ( Ms) up to 14.57 emu/cm3. The saturation magnetization in irradiated thin films is directly correlated to the area under the peak of defect-associated PL emission. The mechanism such as the oxygen vacancy-based F-center exchange model is considered to understand the enhancement of ferromagnetism in ion irradiated CeO2 thin films. Some popular theoretical models are also employed to determine various magnetic parameters.

The Relationship between Photoluminescence Emissions and Photocatalytic Activity of CeO2 Nanocrystals

“…Cerium dioxide (CeO 2 ), or ceria, is one of the most reactive rare earth oxides. It shows excellent properties needed for fabricating resonators, antennas, and filters, such as low dielectric loss and improved Q × f property associated with relatively high dielectric constant values (ε ≈ 29.41), and wide theoretical bandgap energy ( E gap = 6.0 eV). − Due to its unique combination of properties, CeO 2 stands out as an important multifunctional material with applications as gas sensors, , oxygen permeation membranes, , catalysts, solar cells, − coatings, − and biomedicine. , Its characteristic optical absorption edge associated with its broadband photoluminescent (PL) emission in the visible region and ferromagnetic activity, observed in nanostructured CeO 2 , also make it suitable for optoelectronics , and spintronics applications.…”

“…5−8 Due to its unique combination of properties, CeO 2 stands out as an important multifunctional material with applications as gas sensors, 7,8 oxygen permeation membranes, 9,10 catalysts, 11 solar cells, 12−14 coatings, 15−17 and biomedicine. 18,19 Its characteristic optical absorption edge associated with its broadband photoluminescent (PL) emission in the visible region and ferromagnetic activity, observed in nanostructured CeO 2 , also make it suitable for optoelectronics 7,20 and spintronics 21 applications.…”

Study of Radiation-Induced Damage Processes in CeZrO4–YZrO3 Ceramics Caused by Helium Irradiation

“…At the same time, one of the ways to combat these processes is the stabilization of zirconium ceramics with yttrium or cerium, the addition of which leads to an increase in resistance to radiation damage [31][32][33]. In addition, several works [34][35][36] devoted to studying the radiation resistance of CeO 2 ceramics have shown rather excellent prospects for these materials when used as a basis for creating dispersed nuclear fuel. However, despite the sufficient amount of experimental work in this area, many issues still need to be addressed.…”