论文标题
范德华系统中自旋动态的演变$ m _ {\ text {2}} $ p $ _ {\ text {2}} $ s $ s $ _ {\ text {6}} $（$ \ boldsymbol ni $ _ {\ text {2}} $）系列由电子旋转共振光谱探测
Evolution of the spin dynamics in the van der Waals system $M_{\text{2}}$P$_{\text{2}}$S$_{\text{6}}$ ($\boldsymbol{M}_{\text{2}}$ = Mn$_{\text{2}}$, MnNi, Ni$_{\text{2}}$) series probed by electron spin resonance spectroscopy
论文作者
论文摘要
在这项工作中，我们报告了范德华的单重稳定样本的详细ESR光谱研究，复合$ M _ {\ text {2}} $ p $ _ {\ text {2}} $ s $ s $ s $ _ { mn $ _ {\ text {2}} $，mnni，ni $ _ {\ text {2}} $），以9.56 GHz的激发频率进行，以高于磁性顺序的广泛温度，以及相对于样品的磁场的不同方向。分析共振场的温度和角度依赖性以及Mn $ _2 $ _2 $ p $ _2 $ _2 $ s $ _6 $化合物的线宽，我们观察到，旋转动力学的重大变化是从3D样波动的主导地位到接近磁性顺序的主导地位，即在较高温度下的2D类似旋转波动的相对增加。这样的行为与先前研究的Cr $ _ {\ text {2}} $ ge $ _ {\ text {2}} $ te $ _ {\ text {\ text {6}} $相反cr $ _ {\ text {2}} $ ge $ _ {\ text {2}} $ te $ _ {\ text {6}} $。另一方面，MNNIP $ _2 $ s $ _6 $复合物在整个测量温度范围内具有3D样式自旋相关的典型线路的角度依赖性，但是在共振场的温度依赖性和线圈范围内可以看到2D类似的相关性。 ni $ _2 $ p $ _2 $ s $ _6 $又不显示任何2D签名。这表明（Mn $ _ {1-X} $ ni $ _x $）$ _ 2 $ _2 $ p $ _2 $ _2 $ s $ _6 $一个人可以控制交换交互，也可能在第三维度中，将Ni内容变化（Mn $ _ {1-x} $ ni $ _x $）。
In this work we report a detailed ESR spectroscopic study of the single-crystalline samples of the van der Waals compounds $M_{\text{2}}$P$_{\text{2}}$S$_{\text{6}}$ ($M_{\text{2}}$ = Mn$_{\text{2}}$, MnNi, Ni$_{\text{2}}$), performed at an excitation frequency of 9.56 GHz, in a broad range of temperatures above the magnetic order, and at different orientations of the magnetic field with respect to the sample. Analyzing temperature and angular dependences of the resonance field and of the linewidth of the Mn$_2$P$_2$S$_6$ compound we have observed a significant change of the spin dynamics from the dominance of the 3D-like fluctuations close to the magnetic order to a relative increase of the 2D-like spin fluctuations at higher temperatures. Such a behavior, which is opposite to the development of the low-D signatures in the previously studied Cr$_{\text{2}}$Ge$_{\text{2}}$Te$_{\text{6}}$ compound, can be explained by the difference in the type of magnetic order in Mn$_2$P$_2$S$_6$ and Cr$_{\text{2}}$Ge$_{\text{2}}$Te$_{\text{6}}$. On the other hand, MnNiP$_2$S$_6$ compound exhibits angular dependences of the linewidth typical for the system with 3D-like spin correlations in the whole measurement temperature range, however the 2D-like correlations can be seen in the temperature dependences of the resonance field and the linewidth. Ni$_2$P$_2$S$_6$, in turn, does not show any 2D signatures. This suggests that varying the Ni content in (Mn$_{1-x}$Ni$_x$)$_2$P$_2$S$_6$ one can control the exchange interaction, possibly also in the third dimension.
