Micron-scale crystallization of Bi:YIG by laser rapid thermal annealing at controlled atmosphere

Abstract

Rapid thermal annealing (RTA) at 800–900 °C in air atmosphere is commonly used to crystallize bismuth-substituted yttrium iron garnet (Bi:YIG) deposited by vacuum evaporation techniques or metal–organic decomposition. However, the conventional RTA leads to undesirable effects in applications where Bi:YIG is the constituent material of a nano- or microstructure. Here we report on an approach to Bi:YIG local crystallization by a focused continuous wave laser beam (LRTA). The structural and optical properties of micron-sized Bi:YIG stripes crystallized in air, oxygen, nitrogen and argon atmospheres are discussed. The demonstrated LRTA can find practical applications for Bi:YIG monolithic integration on non-garnet substrates.