Title: Magnetic relaxation phenomena in the Chiral Magnet Fe$_{1-x}$Co$_x$Si: An ac susceptibility study Show Chinese title

Title: 手性磁体Fe$_{1-x}$Co$_x$Si中的磁弛豫现象：交流磁化率研究

Abstract: We present a systematic study of the ac susceptibility of the chiral magnet Fe$_{1-x}$Co$_x$Si with $x$ = 0.30 covering four orders of magnitude in frequencies from 0.1 Hz to 1 kHz, with particular emphasis to the pronounced history dependence. Characteristic relaxation times ranging from a few milliseconds to tens of seconds are observed around the skyrmion lattice A-phase, the helical-to-conical transition and in a region above $T_C$. The distribution of relaxation frequencies around the A-phase is broad, asymmetric and originates from multiple coexisting relaxation processes. The pronounced dependence of the magnetic phase diagram on the magnetic history and cooling rates as well as the asymmetric frequency dependence and slow dynamics suggest more complicated physical phenomena in Fe$_{0.7}$Co$_{0.3}$Si than in other chiral magnets. Show Chinese abstract

Abstract: 我们对手性磁体Fe$_{1-x}$Co$_x$Si在$x$= 0.30时的交流磁化率进行了系统研究，覆盖了从0.1 Hz到1 kHz四个数量级的频率，特别强调了明显的历史依赖性。 在自旋涡旋晶格A相、螺旋相到锥形相的转变以及高于$T_C$的区域附近，观察到从几毫秒到几十秒不等的特征弛豫时间。 在A相附近的弛豫频率分布较宽、不对称，并来源于多个共存的弛豫过程。 磁相图对磁历史和冷却速率的明显依赖性，以及不对称的频率依赖性和缓慢的动力学表明，Fe$_{0.7}$Co$_{0.3}$Si中的物理现象比其他手性磁体更为复杂。