{"title":"YxNi2-yMny (0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3) 拉夫相化合物的结构演变和吸氢特性","authors":"Hao Shen, Valérie Paul-Boncour, Ping Li, Lijun Jiang, Junxian Zhang","doi":"10.3390/inorganics12020055","DOIUrl":null,"url":null,"abstract":"The YxNi2−yMny system was investigated in the region 0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3. The alloys were synthesized by induction melting and corresponding annealing. The substitution of Mn for Ni (y = 0.1) favors the formation of a C15 structure with disordered Y vacancies against the superstructure of Y0.95Ni2. For y = 0.2 and 0.3, Mn can substitute in both Y and Ni sites. Single-phase compounds with a C15 structure can be formed by adjusting both the Y and Mn contents. Their hydrogen absorption–desorption properties were measured by pressure–composition isotherm (PCI) measurements at 150 °C, and the hydrides were characterized at room temperature by X-ray diffraction and TG–DSC experiments. The PCIs show two plateaus corresponding to the formation of crystalline and amorphous hydrides. The heating of the amorphous hydrides leads to an endothermic desorption at first and then a recrystallization into Y(Ni, Mn)3 and YHx phases. At higher temperatures, the Y hydride desorbs, and a recombination into a Y(Ni, Mn)2 Laves phase compound is observed. For y = 0.1, vacancy formation in the Y site and partial Mn substitution in the Ni site enhance the structural stability and suppress the hydrogen-induced amorphization (HIA). However, for a larger Mn content (y ≥ 0.2), Mn substitutes also in the Y sites at the expense of Y vacancies. This yields worse structural stability upon hydrogenation than for y = 0.1, as the mean ratio r(Y, Mn)/r(Ni/Mn) becomes larger than for y = 0.1 r(Y, ☐)/r(Ni/Mn).","PeriodicalId":507601,"journal":{"name":"Inorganics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Structural Evolution and Hydrogen Sorption Properties of YxNi2−yMny (0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3) Laves Phase Compounds\",\"authors\":\"Hao Shen, Valérie Paul-Boncour, Ping Li, Lijun Jiang, Junxian Zhang\",\"doi\":\"10.3390/inorganics12020055\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The YxNi2−yMny system was investigated in the region 0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3. The alloys were synthesized by induction melting and corresponding annealing. The substitution of Mn for Ni (y = 0.1) favors the formation of a C15 structure with disordered Y vacancies against the superstructure of Y0.95Ni2. For y = 0.2 and 0.3, Mn can substitute in both Y and Ni sites. Single-phase compounds with a C15 structure can be formed by adjusting both the Y and Mn contents. Their hydrogen absorption–desorption properties were measured by pressure–composition isotherm (PCI) measurements at 150 °C, and the hydrides were characterized at room temperature by X-ray diffraction and TG–DSC experiments. The PCIs show two plateaus corresponding to the formation of crystalline and amorphous hydrides. The heating of the amorphous hydrides leads to an endothermic desorption at first and then a recrystallization into Y(Ni, Mn)3 and YHx phases. At higher temperatures, the Y hydride desorbs, and a recombination into a Y(Ni, Mn)2 Laves phase compound is observed. For y = 0.1, vacancy formation in the Y site and partial Mn substitution in the Ni site enhance the structural stability and suppress the hydrogen-induced amorphization (HIA). However, for a larger Mn content (y ≥ 0.2), Mn substitutes also in the Y sites at the expense of Y vacancies. This yields worse structural stability upon hydrogenation than for y = 0.1, as the mean ratio r(Y, Mn)/r(Ni/Mn) becomes larger than for y = 0.1 r(Y, ☐)/r(Ni/Mn).\",\"PeriodicalId\":507601,\"journal\":{\"name\":\"Inorganics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-02-07\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Inorganics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3390/inorganics12020055\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3390/inorganics12020055","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
摘要
研究了 0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3 区域内的 YxNi2-yMny 系统。合金是通过感应熔化和相应的退火工艺合成的。用锰代替镍(y = 0.1)有利于形成带有无序 Y 空位的 C15 结构,而不是 Y0.95Ni2 的上层结构。当 y = 0.2 和 0.3 时,锰可同时取代 Y 和 Ni 位点。通过调整 Y 和 Mn 的含量,可以形成具有 C15 结构的单相化合物。它们的氢吸收-解吸特性是在 150 °C 下通过压力-沉积等温线(PCI)测量得到的,氢化物在室温下的特性则是通过 X 射线衍射和 TG-DSC 实验得到的。PCI 显示出两个高原,分别对应于结晶水化物和无定形水化物的形成。加热无定形氢化物首先导致内热解吸,然后再结晶成 Y(Ni,Mn)3 和 YHx 相。在较高温度下,Y 氢化物解吸,并重新结合成 Y(Ni,Mn)2 Laves 相化合物。当 y = 0.1 时,Y 位点的空位形成和镍位点的部分锰置换增强了结构的稳定性,并抑制了氢致非晶化(HIA)。然而,当锰含量较高时(y≥ 0.2),锰也会取代 Y 位点,而牺牲 Y 空位。这导致氢化时的结构稳定性比 y = 0.1 时更差,因为平均比率 r(Y,Mn)/r(Ni/Mn)变得比 y = 0.1 时的 r(Y,☐)/r(Ni/Mn)更大。
Structural Evolution and Hydrogen Sorption Properties of YxNi2−yMny (0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3) Laves Phase Compounds
The YxNi2−yMny system was investigated in the region 0.825 ≤ x ≤ 0.95, 0.1 ≤ y ≤ 0.3. The alloys were synthesized by induction melting and corresponding annealing. The substitution of Mn for Ni (y = 0.1) favors the formation of a C15 structure with disordered Y vacancies against the superstructure of Y0.95Ni2. For y = 0.2 and 0.3, Mn can substitute in both Y and Ni sites. Single-phase compounds with a C15 structure can be formed by adjusting both the Y and Mn contents. Their hydrogen absorption–desorption properties were measured by pressure–composition isotherm (PCI) measurements at 150 °C, and the hydrides were characterized at room temperature by X-ray diffraction and TG–DSC experiments. The PCIs show two plateaus corresponding to the formation of crystalline and amorphous hydrides. The heating of the amorphous hydrides leads to an endothermic desorption at first and then a recrystallization into Y(Ni, Mn)3 and YHx phases. At higher temperatures, the Y hydride desorbs, and a recombination into a Y(Ni, Mn)2 Laves phase compound is observed. For y = 0.1, vacancy formation in the Y site and partial Mn substitution in the Ni site enhance the structural stability and suppress the hydrogen-induced amorphization (HIA). However, for a larger Mn content (y ≥ 0.2), Mn substitutes also in the Y sites at the expense of Y vacancies. This yields worse structural stability upon hydrogenation than for y = 0.1, as the mean ratio r(Y, Mn)/r(Ni/Mn) becomes larger than for y = 0.1 r(Y, ☐)/r(Ni/Mn).