Search

Laser ablated zinc ferrite (ZnFe 2 O 4 ) films deposited at O 2 pressure of 0.16 mbar onto fused quartz substrates are nanocrystalline and display net magnetic moment dependent on the substrate temperature (T s ) during deposition. At T s = 350 °C, the room 4πM s reached the maximum of 3 kG. The films were studied by spectral ellipsometry and magnetooptical (MO) Kerr effect spectroscopy at photon energies between 1 and 5 eV at room temperature in the longitudinal magnetic flux density 1.14 T. The optical and MO spectra show structural details typical for inverted spinels. Our ZnFe 2 O 4 samples display amplitudes somewhat reduced with respect to those in other ferrimagnetic oxides with the exchange coupled Fe3+ pairs, i.e., in Li 0.5 Fe 2.5 O 4 and MgFe 2 O 4 spinel ferrite and magnetoplumbite, PbFe 12 O 19 . The lower amplitudes are probably due to the interplay of nanocrystalline nature and lower degree of spinel inversion in the ZnFe 2 O 4 laser ablated films.

The properties of nanometer-thick yttrium iron garnet (YIG) films are strongly influenced by interfaces. This work employs spectral ellipsometry (SE) and magneto-optic polar Kerr rotation (PKR) to characterize YIG films with thickness, t, from 6 nm to 30 nm grown on Gd3Ga5O12 (GGG) substrates oriented parallel to (111) plane. The films display a surface roughness of 0.35 nm or lower. The analysis of the SE data at the photon energies of 1 eV

Nanometer (nm)-thick yttrium iron garnet (Y3Fe5O12, YIG) films present interest for spintronics. This work employs spectral ellipsometry and magneto-optic Kerr effect (MOKE) spectra to characterize nm-thick YIG films grown on single-crystal Gd3Ga5O12 substrates by magnetron sputtering. The thickness (t) of the films ranges between 10 nm and 40 nm. Independent on t, the polar MOKE hysteresis loops saturate in the field of about 1.8 kOe, consistent with the saturation magnetization in bulk YIG (4πMs ≈ 1.75 kG). The MOKE spectrum measured at photon energies between 1.3 eV and 4.5 eV on the 38-nm-thick film agrees with that measured on single-crystal YIG bulk materials. The MOKE spectrum of the 12-nm-thick film still preserves the structure of the bulk YIG but its amplitude at lower photon energies is modified due to the fact that the radiation penetration depth exceeds 20 nm. The t dependence of the MOKE amplitude is consistent with MOKE calculations. The results indicate that the films are stoichiometric, s...