论文标题
旋转冰冻的出现在dy $ _2 $ ti $ _ {1.8} $ mn $ _ {0.2} $ o $ $ _7 $
Emergence of Spin Ice freezing in Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$
论文作者
论文摘要
我们在本文中介绍了填充polycrystalline化合物的自旋冷冻动力学$ _2 $ _2 $ _ {1.8} $ mn $ _ {0.2} $ o $ $ _7 $。在dy $ _2 $ _2 $ _2 $ o $ _7 $中，在3 k（t $ _i $）的温度下与冰状的旋转放松以及在0.7 k左右的温度下进行另一个旋转冷冻（t \ t \ textless t $ _i $）。通过应用不同的直流磁场偏置和应用的交流场的应用，可以显着观察到这些弛豫。我们在这里表明，随着在Ti网站的分数包含在Dy $ _2 $ _2 $ _2 $ o $ _7 $的情况下，这些温度有很大的转变。在dy $ _2中，$ _ {1.8} $ mn $ _ {0.2} $ o $ _7 $ t $ _i $ the t $ _i $转移到较高的温度左右，在5 k左右的冻结，属于T \ Textless t $ _i $的冷冻转移到2.5 k，而没有任何外部DC偏见和/或AC-Field的应用。与dy $ _2 $ _2 $ _2 $ _2 $ o $ _7 $相比，在Ti网站上包含MN还增强了DY $ _2 $ _2 $ _2 $ _ {1.8} $ Mn $ _ {0.2} $ _7 $的铁磁相互作用。 Arrhenius的冷冻温度适合DY $ _2 $ ti $ _ {1.8} $ Mn $ _ {0.2} $ o $ _7 $，表明这些自旋放松在t $ _i $和T \ t \ textless t $ _i $中表明这些旋转放松是热诱导的。已经使用Synchrotron X射线衍射研究了晶格参数和晶体磁场偶联的低温结构变化。 Debye-Gruineisen的温度依赖性晶格量的分析显示，在更高的温度（70 K）中，晶体场声子耦合的出现在DY $ _2 $ _2 $ _2 $ _2 $ _ {1.8} $ _ {1.8} $ MN $ _ {0.2} $ _ {0.2} $ $ $ $ _7 $相反，与40 K相反，在DY $ _2 $ _2 $ _2 $ _2 $ __2 $ _2 $ _7 $中，这些发现使dy $ _2 $ ti $ _ {1.8} $ mn $ _ {0.2} $ o $ _7 $成为合适的系统，可在可行的温度下探索旋转冰现象的应用。
We herein present the spin freezing dynamics of stuffed polycrystalline compound Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$. In Dy$_2$Ti$_2$O$_7$, spin freezes with ice-like spin relaxations at a temperature around 3 K (T$_i$) along with another spin freezing at a temperature around 0.7 K (T\textless T$_i$). These relaxations can be observed prominently with an application of varying DC magnetic field bias and applied AC-field. We show here that with fractional inclusion of Mn at the Ti site in Dy$_2$Ti$_2$O$_7$, there is a significant shift in these temperatures. In Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$ the T$_i$ shifts to a higher temperature around 5 K and freezing belonging to T\textless T$_i$ shifts to 2.5 K without any application of external DC Bias and/or AC-field. The inclusion of Mn at Ti site also enhances the ferromagnetic interaction for Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$ as compared to Dy$_2$Ti$_2$O$_7$. Arrhenius fit of freezing temperature with frequency for Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$ shows that these spin relaxations at T$_i$ and T\textless T$_i$ are thermally induced. Low-temperature structural change in lattice parameters and crystal field phonon coupling has been studied using synchrotron x-ray diffraction. Debye-Gruineisen analysis of temperature-dependent lattice volume shows the emergence of crystal field phonon coupling at a much higher temperature (70 K) in Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$ in contrast to 40 K in Dy$_2$Ti$_2$O$_7$. These findings make Dy$_2$Ti$_{1.8}$Mn$_{0.2}$O$_7$ a suitable system to explore the application of the spin ice phenomenon at a workable temperature.
