论文标题
$ \ rm eupd_3s_4 $和$ \ rm（y，la）_xeu_ {1-x} pd_3s_4 $中的价和磁性
Valence and magnetism in $\rm EuPd_3S_4$ and $\rm (Y,La)_xEu_{1-x}Pd_3S_4$
论文作者
论文摘要
$^{151} $euMössbauer光谱验证表明，混合价值$ \ rm中的yttrium替换eupd_3s_4 $驱动了欧盟$^{3+} $的最初50:50混合物的最初50:50组合，而eu $ $^{2+_ 50 \％。我们发现总价电子计数和化学压力效应无法解释观察到的行为，但是保存细胞体积提供了对欧盟$^{2+} $的变化的一致描述：eu $^{3+} $比率。值得注意的是，灯笼替代也导致从较低温度下的静态混合价值行为到较高温度下的动态混合情人行为的明确过渡，并且对于纯$ \\ $ \ \ \ rm flm $ \ flm $ \ \ rm flm opd_3s_3s_4 $ compound，发作温度随着EU含量而单调升高，并推出$ \ sim $ 340〜K。尽管磁性顺序在两个系列中至少持续到x = 0.875，尽管持续的欧盟$^{2+} $离子的量急剧减少。
$^{151}$Eu Mössbauer spectroscopy shows that yttrium substitution in mixed-valent $\rm EuPd_3S_4$ drives the initial 50:50 mix of Eu$^{3+}$ and Eu$^{2+}$ towards pure Eu$^{2+}$, whereas lanthanum substitution has the opposite effect, but only for substitution levels above 50\%. We find that total valence electron count and chemical pressure effects cannot account for the observed behaviour, however conserving the cell volume provides a consistent description of the changes in the Eu$^{2+}$:Eu$^{3+}$ ratio. Remarkably, lanthanum substitution also leads to a clear transition from static mixed-valent behavior at lower temperatures to dynamic mixed valent behavior at higher temperatures, with the onset temperature monotonically increasing with Eu content and extrapolating to a value of $\sim$340~K for the pure $\rm EuPd_3S_4$ compound. Magnetic order persists at least as far as x=0.875 in both series, despite the drastic reduction in the amount of moment-carrying Eu$^{2+}$ ions.
