论文标题
几何沮丧的srgd $ _2 $ o $ _4 $源自粉末和单晶中子衍射的磁性结构
Magnetic structures of geometrically frustrated SrGd$_2$O$_4$ derived from powder and single-crystal neutron diffraction
论文作者
论文摘要
我们介绍了SRGD $ _2 $ o $ _4 $的低温磁结构，结合了含有$^{160} $ GD同位素的多晶和单晶样品上的中子衍射方法。与SR $ LN_2 $ o $ $ _4 $ family（$ ln $ = Lanthanide）的其他成员相反，该系统揭示了两个长距离有序的磁性阶段，我们的衍射数据明确识别了。 $ t _ {\ rm n1} $ = 2.73〜K，a $ \ mathbf {q} _1 $ =（0 0 0）磁性结构是稳定的，沿着$ c $ axis（太空组$ pnam）的铁磁链与相邻的链构成了抗fifermagnet，在$ c $ axis（太空组$ pnam）的情况下稳定。在$ t _ {\ rm n2} $ = 0.48〜K下冷却下来时，由$ \ Mathbf {q} _2 $ =（0〜0〜0.42）调制的附加不相称的组件在两种不同的GD位置中都与垂直轴相连，从而在范围内呈垂直的轴，从而在粉丝般的磁场中呈现。通过对作用在该位点上的晶体场进行详细分析，可以促进具有具有中子衍射的磁顺序的特定GD位点的鉴定。观察到的排序现象强调了该系统中复杂的多轴各向异性。
We present the low-temperature magnetic structures of SrGd$_2$O$_4$ combining neutron diffraction methods on polycrystalline and single-crystal samples containing the $^{160}$Gd isotope. In contrast to other members of the Sr$Ln_2$O$_4$ family ($Ln$ = lanthanide) this system reveals two long-range ordered magnetic phases, which our diffraction data unambiguously identify. Below $T_{\rm N1}$ = 2.73~K, a $\mathbf{q}_1$ = (0 0 0) magnetic structure is stabilized where ferromagnetic chains along the $c$~axis (space group $Pnam$) are coupled antiferromagnetically with neighboring chains. On cooling below $T_{\rm N2}$ = 0.48~K, an additional incommensurate component modulated by $\mathbf{q}_2$ = (0~0~0.42) evolves and aligned along either of the perpendicular axes for the two different Gd sites, resulting in a fan-like magnetic structure. The identification of the particular Gd sites with the magnetic order observed with neutron diffraction is facilitated by a detailed analysis of the crystal fields acting on the sites. The observed ordering phenomena underline the complex multiaxial anisotropy in this system.
