Composition and microstructure of holmium monosulfide compacts processed by reaction sintering
Composition and microstructure of holmium monosulfide compacts processed by reaction sintering
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反应烧结一硫化钬压坯的成分与显微结构
DOI：
10.1016/j.jallcom.2020.157872
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发表时间：
2021
影响因子：
6.2
通讯作者：
Kawamura Yukihiro
中科院分区：
文献类型：
--
作者：
Bien Tran Nhu;Hirai Shinji;Vasilyeva Inga G.;Nikolaev Ruslan;Sekine Chihiro;Kamegawa Atsunori;Wakiya Kazuhei;Kawamura Yukihiro
一硫化钬（HoS）具有独特的反铁磁性，是一种在电子和磁记录器件中具有潜在应用前景的材料。由于Ho和S的蒸气压相差很大，所以Ho与S直接相互作用的HoSx合成并不总是达到均匀状态。本文报道了用脉冲电流烧结装置由Ho_2S_3和Ho直接反应合成Ho_x（0.68 ≤x≤ 1.2）。在1973 K的烧结温度下，当Ho金属的制备比例为16.16（HoS 1.19）至38.15（HoS 0.99）质量%时，获得了HoS单相的烧结体。Ho添加对晶格常数，熔点，和电阻率的影响进行了研究内的均匀范围内的HoS相。因此，我们发现，晶格常数和熔化温度逐渐增加，当组成接近化学计量组成，并达到5.458欧姆和2608 K的HoS1.01，分别的值。除了HoS0.99外，所有均匀的HoSx压坯在低于50 K时都表现出金属行为，而在低于20 K时可以观察到类似于热膨胀的上升。另一方面，HoS0.99在4K下表现出金属行为，这表明晶格不完整性对HoSx的电学性质有很大影响。结果表明，该烧结工艺制备出的致密、界面独特的HoSx复合材料具有明显的优越性。
With its specific physical property of antiferromagnetism, holmium monosulfide (HoS) is considered as an attractive material for potential application in electronic and magnetic recording devices. The HoSxsynthesis through the direct interaction of the Ho metal with S does not always attain a homogeneous state because of the large difference between the vapor pressures of Ho and S. We report herein the HoSxsynthesis (0.68 ≤x≤ 1.2) by the direct reaction of Ho2S3and Ho using a pulse electric current sintering apparatus. The sintering compacts of the HoS single phase are obtained when the preparation ratios of the Ho metal range from 16.16 (HoS1.19) to 38.15 (HoS0.99) mass% at a sintering temperature of 1973 K. The effect of the Ho addition on the lattice constant, melting point, and electrical resistivity is studied within the homogeneity range of the HoS phase. Consequently, we found that the lattice constant and the melting temperature gradually increase when the composition is close to the stoichiometric composition and reach the values of 5.458 Å and 2608 K of HoS1.01, respectively. All the homogeneous HoSxcompacts, except HoS0.99, show metallic behaviors down to 50 K, whereas a semiconducting-like upturn can be observed below 20 K. On the other hand, HoS0.99shows a metallic behavior to 4 K, which indicates that the lattice imperfection considerably affects the electric properties of HoSx. The advantages of the sintering process for the HoSxcompact preparation with higher density and a peculiar interface are demonstrated.