Cold sintering with dimethyl sulfoxide solutions for metal oxides
Cold sintering with dimethyl sulfoxide solutions for metal oxides
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DOI：
10.1007/s10853-019-03410-1
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发表时间：
2019-05-01
影响因子：
4.5
通讯作者：
Maria, Jon-Paul
中科院分区：
文献类型：
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作者：
Kang, Xiaoyu;Floyd, Richard;Maria, Jon-Paul
以二甲亚砜（DMSO）为基础，研究了ZnO和MnO的冷烧结。对于ZnO陶瓷，在180℃下用DMSO-HOAc和DMSO-Zn(OAc)(2)溶液冷烧结时，密度值接近99%的理论值。用HOAc水溶液致密化MnO可以产生84%理论密度的陶瓷，其中含有大量的Mn(OH)(2)次级相。相比之下，使用DMSO-HOAc溶液在250℃下产生94%的理论密度值，并通过x射线衍射验证微量Mn3O4。扫描电子显微镜分析含有Mn3O4的试样断口表面，发现许多小于100 nm的晶体在相当大的起始MnO晶粒上或之间成核。随着温度的升高，这些沉淀物开始合并并填充初始压实后的孔隙。这些结果确定了冷烧结金属氧化物的途径，在水介质的存在下，有利于氢氧化物的形成，从而抑制进一步致密化。
Cold sintering of ZnO and MnO with dimethyl sulfoxide (DMSO)-based solutions is demonstrated. For ZnO ceramics, density values approach 99% theoretical when cold-sintered at 180 degrees C with DMSO-HOAc and DMSO-Zn(OAc)(2) solutions. MnO densified with aqueous HOAc solutions produces ceramics of 84% theoretical density that contain significant amounts of Mn(OH)(2) secondary phases. In comparison, using DMSO-HOAc solutions produces density values of 94% theoretical at 250 degrees C with trace quantities of Mn3O4, verified via X-ray diffraction. Scanning electron microscope analysis of sample fracture surfaces containing Mn3O4 reveals numerous crystallites smaller than 100 nm that nucleate on or between the considerably larger starting MnO grains. With increasing temperature, these precipitates appear to coalesce and fill the porosity that remains after initial compaction. These results identify an avenue to cold sinter metal oxides that, in the presence of aqueous media, favor hydroxide formation which inhibits further densification.