Elastic Recoil Analysis of Hydrogen in Ion-Implanted Magnetic Bubble Garnets Using 44 MeV Chlorine Ions

Abstract

Elastic recoil analysis using 44 MeV chlorine ions is a precise and timesaving method of measuring hydrogen profiles of ion implanted magnetic bubble garnets. Neon, nitrogen and hydrogen ion-implanted modified yttrium iron garnets, which are used for magnetic bubble devices based on ion implanted propagation patterns, (I2P2), were studied with respect to their hydrogen concentration-depth distributions. A description and calibration of the elestic recoil analysis setup are presented along with the necessary simple algorithms to obtain the final hydrogen concentration-depth profiles from the measured energy spectra generated by recoiled protons. The garnet samples were annealed with or without a surface coating of SiO₂. At 250°C, the hydrogen was found to diffuse throughout the aamaged surface layer but not into the underlying undamaged material. At 350°C, the hydrogen diffused out of the uncoated garnet, but was sealed into the implant damaged garnet layer by the thin oxide coating. Such hydrogen retention correlates with previously reported beneficial effects of an oxide layer deposited at a low temperature after implantation but before processing on ion implanted bubble devices.