论文标题
Nixfe100-X薄膜中超快自旋进动的磁弹性驱动的相位反转
Magnetoelasticity-driven phase inversion of ultrafast spin precession in NixFe100-x thin films
论文作者
论文摘要
我们为磁弹性在铁电磁Nixfe100-X合金膜的超快自旋动力学中的确定性作用提供了有力的证据。没有晶体结构的变化，我们观察到X = 87.0-97.5范围内的自旋进动的突然PI期反转。此外，发现该相通过改变泵的通量来不断地改变并逆转其标志。这些不能简单地通过磁晶的温度依赖性，消除电磁和Zeeman场的温度依赖性来解释，这些田地在描述旋转动力学时通常考虑到了迄今为止考虑的。通过温度和成分依赖性模拟，添加了由晶格热应变产生的磁弹性场，我们透露，常规和磁弹性场围绕X = 95.3竞争，其中自旋动力学显示最大的相位移位。为了进行分析理解，我们进一步表明，证明是最重要的宏观参数的居里温度，饱和磁化和磁截图的温度依赖性相互作用，这些相互作用确定了超快自旋动力学。我们广泛的研究强调，磁弹性是充分理解超快自旋动态驱动机制的关键要素。
We present strong evidences for the deterministic role of magnetoelasticity in ultrafast spin dynamics of ferromagnetic NixFe100-x alloy films. Without a change in the crystal structure, we observed sudden Pi-phase inversion of the spin precession in the range of x = 87.0 - 97.5. In addition, it was found that the phase was continuously changed and reversed its sign by varying the pump fluence. These cannot be explained simply by temperature dependence of magnetocrystalline, demagnetizing, and Zeeman fields which have been conventionally considered so far in describing the spin dynamics. Through the temperature- and composition-dependent simulations adding the magnetoelastic field generated from the lattice thermal strain, we revealed that the conventional and magnetoelastic fields were competing around x = 95.3, where the spin dynamics showed the largest phase shift. For analytic understanding, we further show that the temperature-dependent interplay of the Curie temperature, saturation magnetization, and magnetostriction, which are demonstrated to be the most important macroscopic parameters, determines the ultrafast spin dynamics. Our extensive study emphasizes that magnetoelasticity is the key ingredient for fully understanding the driving mechanism of ultrafast spin dynamics.
