Ultra Thin Films of Yttrium Iron Garnet with Very Low Damping: A Review

Thin film Yttrium Iron Garnet (YIG) is a promising material for integrated magnonics. To introduce YIG into nanofabrication processes it is necessary to fabricate very thin YIG films with a thickness well below 100 nm while retaining the extraordinary magnetic properties of the material, especially its long magnon lifetime and spin wave propagation length. Herein, a brief introduction into the topic is given and the various results published over the last decade in this area are reviewed and discussed. Especially for ultrathin films it turns out that pulsed layer deposition and sputtering are the most promising candidates. In addition, the application of room‐temperature deposition and annealing for lift‐off based nanopatterning is discussed, as well as the properties of nanostructures obtained by this method over the past years. Different ways to deposit ultrathin Yttrium Iron Garnet (YIG) films with low damping and narrow ferromagnetic resonance linewidth, which were developed over the last decade, are discussed. A number of results are assessed and compared. Also recent results on YIG nanopatterning by lift‐off are presented.