Abstract
We have investigated recrystallization of amorphous Yttrium Iron Garnet (YIG) by annealing in oxygen atmosphere. Our findings show that well below the melting temperature the material transforms into a fully epitaxial layer with exceptional quality, both structural and magnetic. In ferromagnetic resonance (FMR) ultra low damping and extremely narrow linewidth can be observed. For a 56 nm thick layer a damping constant of alpha = (6.15 +/- 1.50) . 10(-5) is found and the linewidth at 9.6 GHz is as small as 1.30 +/- 0.05 Oe which are the lowest values for PLD grown thin films reported so far. Even for a 20 nm thick layer a damping constant of a = (7.35 +/- 1.40) . 10(-5) is found which is the lowest value for ultrathin films published so far. The FMR linewidth in this case is 3.49 +/- 0.10 Oe at 9.6 GHz. Our results not only present a method of depositing thin film YIG of unprecedented quality but also open up new options for the fabrication of thin film complex oxides or even other crystalline materials.