Annealing behavior of hydrogen-implanted magnetic garnet

Abstract

Ferromagnetic resonance spectra and x-ray rocking curves were used to measure magnetic and strain profiles of Gd, Tm, Ga substituted yttrium iron garnet films implanted with H₂⁺ at 120 keV and at doses in the range (3–80)×10^15 ions/cm^2. The maximum strain occurred at a depth of 3600 Å, reaching a value of 2.9% at 40×10^15 ions/cm^2. At the highest dose, the garnet was amorphous in that region which had highest strain at lower dose. The strain has two components, one due to damage and one due to the presence of the hydrogen atoms. The second component disappears for annealing temperatures above 400 °C, at which temperature the hydrogen has been reported to be largely desorbed. The reduction of the first component with annealing follows the same pattern as other implant elements. The magnetic anisotropy exhibits a large anomalous nonlinear increase with dose. The excess over other implantation elements disappears for annealing temperatures above 400 °C. There is no significant change in gyromagnetic ratio with dose or annealing temperatures up to 600 °C.