Hydrogen-Insertion-Induced Itinerant Ferromagnetism in Zr2CoH4.8 with Co Chains
Hydrogen-Insertion-Induced Itinerant Ferromagnetism in Zr2CoH4.8 with Co Chains
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DOI：
10.1021/acs.jpcc.9b03793
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发表时间：
2019-06
期刊：
影响因子：
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通讯作者：
H. Mizoguchi;S. Matsuishi;Sang-Won Park;H. Hosono
中科院分区：
文献类型：
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作者：
H. Mizoguchi;S. Matsuishi;Sang-Won Park;H. Hosono
已知的是，采用Al 2Cu型晶体结构的金属间化合物Zr 2Co在Tc = 5.6K下表现出超导性，并且能够实现拓扑异构氢插入。尽管氢插入过渡金属的合金/金属间化合物中经常阻止磁自旋的有序化，但Matar已经基于Stoner条件理论上预测了Zr 2CoH 5中的铁磁自旋有序化[Matar，S. F.、Intermetallics 2013，36，25]。我们证实了氢在~ 300 °C下嵌入/脱嵌到Zr 2Co中，保持母体Al 2Cu型结构。我们已经成功地在实验上确定了在Zr2CoH4.8在Tc = 128 K的铁磁转变，以及在Zr 2Co的超导电性。在2 K时的磁化强度为10.3 μB，但在5.5 kOe时仍未饱和。在磁化曲线分析的基础上，我们证实了Zr_2CoH_（4.8）的弱巡游铁磁性是由自旋涨落引起的。这种氢化物具有一个孤立的钴链，沿着四配位轴与dCo-Co插入。
It is known that an intermetallic, Zr2Co adopting an Al2Cu-type crystal structure, exhibits superconductivity at Tc = 5.6 K and can enable topotactic hydrogen insertion. Although hydrogen insertion into alloys/intermetallics of transition metal often prevents ordering of magnetic spin, Matar has theoretically predicted ferromagnetic spin ordering in Zr2CoH5 based on Stoner conditions [Matar, S. F., Intermetallics 2013, 36, 25]. We confirmed intercalation/deintercalation of hydrogen into Zr2Co at ∼300 °C, keeping the parent Al2Cu-type structure. We have succeeded in experimentally identifying a ferromagnetic transition in Zr2CoH4.8 at Tc = 128 K, as well as superconductivity in Zr2Co. The magnetization at 2 K was ∼0.3μB, although it did not saturate up to 5.5 kOe, even at 2 K. On the basis of analysis of magnetization curves, we confirmed the weak itinerant ferromagnetism of Zr2CoH4.8 derived from spin fluctuation. This hydride has an isolated Co chain running along the tetragonal c axis with a dCo–Co intr...