在兰他尼德-有机合金中的可调的价值对称性
Maja A Dunstan1, Anna S Manvell2, Nathan J Yutronkie3
1Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark. majdu@kemi.dtu.dk.
Nature chemistry
|February 20, 2024
概括
研究人员发现,在兰坦化协调聚合物中,一种罕见的温度诱导的价值分离体 (VT) 过渡发生. 在SmI中这种可切换的价值现象2(pyrazine) 3允许可调节的磁性材料具有可调节的过渡温度.
科学领域:
- 材料科学 材料科学 材料科学
- 无机化学 无机化学 有机化学
- 固态物理 固态物理
背景情况:
- 兰化物 (Ln) 离子的独特电子结构对于先进材料至关重要.
- 三价兰坦化物很常见,但改变价值电子数量可以大大改变材料的性质.
- 涉及Ln(III) Ln(II) 开关的价值对称 (VT) 过渡很少见,但具有可调节的特性.
研究的目的:
- 为了研究温度诱导的定体转换在以兰他尼德为基础的协调聚合物.
- 探索通过操纵兰化物价值状态来创造可切换磁性材料的潜力.
- 展示一种化学调节这些材料的过渡温度的方法.
主要方法:
- 合成一种以兰他尼德为基础的协调聚合物SmI2 ((pyrazine) 3.
- 研究温度诱导的价值切换通过氧化还原相互转换的Sm (II) /Sm (III) 和pyrazine物种.
- 将材料与Yb(II) 合金,以产生Sm1-xYbxI2(pyrazine) 3固体溶液.
主要成果:
- 在SmI2(pyrazine) 3中观察到突然和歇斯底里的静脉转变,由Sm(II) /Sm(III) 氧化还原变化驱动.
- 合成的Sm1-xYbxI2(pyrazine) 3固体溶液呈现出异形结构.
- 固体溶液中VT过渡的临界温度可以在环境压力下从200K调整到大约50K.
结论:
- 已经证明了一个简单的策略,用于创建基于兰坦化物价值转换的可热切换磁性材料.
- 通过合金进行化学调,可以精确控制过渡温度.
- 这项工作为设计具有可切换电子和磁性特性的先进功能材料开辟了道路.
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