This letter reports the development of low-damping yttrium-iron-garnet (YIG) thin films via sputtering. The films were deposited by sputtering at room temperature first and were then annealed in O2 at high temperature. It is found that the annealing temperature critically affects the structural properties of the YIG films and thereby dictates the static and dynamic properties of the films. A 75 nm thick YIG film annealed at 900 °C shows an rms surface roughness of 0.08 nm, a coercivity of only 14 A/m (or 0.18 Oe), a saturation induction of 0.1778 T (or 1778 G), which is very close to the bulk value, a gyromagnetic ratio of 2.82 × 104 MHz/T (or 2.82 MHz/Oe), which almost matches the standard value, and a Gilbert damping constant of α ≈ 5.2 × 10–5, which is the lowest among the values reported so far for magnetic films in the nanometer thickness range. Frequency-dependent ferromagnetic resonance measurements with different field orientations confirmed that two-magnon scattering, if present, is very weak, and the measured damping value represents the actual damping of the YIG film.

中文翻译：

---

低阻尼钇铁石榴石薄膜的溅射生长

这封信报告了通过溅射开发低阻尼钇铁石榴石 (YIG) 薄膜。薄膜首先在室温下通过溅射沉积，然后在 O2 中高温退火。发现退火温度严重影响 YIG 薄膜的结构特性，从而决定薄膜的静态和动态特性。在 900 °C 下退火的 75 nm 厚 YIG 膜显示 rms 表面粗糙度为 0.08 nm，矫顽力仅为 14 A/m（或 0.18 Oe），饱和电感为 0.1778 T（或 1778 G），非常接近对于体积值，2.82 × 104 MHz/T（或 2.82 MHz/Oe）的旋磁比几乎与标准值匹配，并且吉尔伯特阻尼常数 α ≈ 5.2 × 10–5，这是迄今为止纳米厚度范围内磁性薄膜报告的值中最低的。具有不同场方向的频率相关铁磁共振测量证实了双磁振子散射（如果存在）非常弱，并且测量的阻尼值代表 YIG 膜的实际阻尼。