Electrical Conductivity, DSC, XRD, and 7Li NMR Studies of Rotator Crystals n-C21H43COOLixK(1-x) (0.33 ≤ x ≤ 0.50), n-CmH(2m+1)COOLi, and n-CmH(2m+1)COOK (m = 13, 15, 17, 19, and 21)
Electrical Conductivity, DSC, XRD, and 7Li NMR Studies of Rotator Crystals n-C21H43COOLixK(1-x) (0.33 ≤ x ≤ 0.50), n-CmH(2m+1)COOLi, and n-CmH(2m+1)COOK (m = 13, 15, 17, 19, and 21)
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电导率，DSC（m = 13、15、17、19 和 21）
DOI：
10.1007/s10751-012-0670-z
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发表时间：
2013
影响因子：
--
通讯作者：
and Satoru Hirakawa
中科院分区：
文献类型：
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作者：
Tomoyuki Hayasaki;Hisashi Honda;and Satoru Hirakawa
n-CmH(2m+ 1)COOM 固体 (M = Li, Na, K;m= 13, 15, 17, 19, 21) 和混合的差示扫描量热 (DSC) 热分析图、X 射线衍射 (XRD) 分析、电导率 (σ) 和 7Li NMR 光谱表征晶体n-C21H43COOLixK(1 −x)(0.25 ≤x≤ 0.75)作为温度的函数进行计算。 n-CmH(2m+ 1)COOM 的 DSC 热分析图揭示了几种具有大熵变的固-固相变。电导率研究表明 n-CmH(2m+ 1)COOLi 晶体是不良电导体。相比之下，n-CmH(2m+ 1)COOK盐的σ值为10− 7–10− 8S·cm− 1。由于n-CmH(2m+ 1)COOLi和n-CmH(2m+ 1)COOK晶体的晶体结构和相变温度相似，因此它们能够与n-CmH(2m+ 1)COOK盐形成混晶。结构n-CxH(2m+ 1)COOLixK(1 −x)。混合晶体的 DSC 热分析图显示，熔点处的熵变较小（ΔSmp< 13 J K− 1mol− 1），此外，固-固相转变温度处的 ΔS 值较大。混合晶体获得的σ值比n-C21H43COOK晶体的σ值大约大一个数量级。在不同温度下记录的混合晶体的7Li NMR谱表明Li + 离子的自扩散在最高温度的固相中被激发。基于这些结果，我们将这些混合晶体归类为旋转晶体。
Differential scanning calorimetry (DSC) thermograms, X-ray diffraction (XRD) analysis, electrical conductivity (σ), and7Li NMR spectroscopy characterization ofn-CmH(2m+ 1)COOM solids (M = Li, Na, K;m= 13, 15, 17, 19, 21) and mixed crystalsn-C21H43COOLixK(1 −x)(0.25 ≤x≤ 0.75) was performed as a function of temperature. DSC thermograms ofn-CmH(2m+ 1)COOM revealed several solid-solid phase transitions with large entropy changes. Electrical conductivity studies established thatn-CmH(2m+ 1)COOLi crystals are poor electrical conductors. In contrast,n-CmH(2m+ 1)COOK salts were found to haveσvalues of 10− 7–10− 8S·cm− 1. Since the crystal structures and phase-transition temperatures of bothn-CmH(2m+ 1)COOLi andn-CmH(2m+ 1)COOK crystals were similar, they were able to form mixed crystals with the structuren-CxH(2m+ 1)COOLixK(1 −x). DSC thermograms of the mixed crystals showed a small entropy change at the melting point (ΔSmp< 13 J K− 1mol− 1), in addition, large ΔSvalues at the solid-solid phase transition temperature. Theσvalues obtained for mixed crystals were roughly one order of magnitude greater than those determined forn-C21H43COOK crystals.7Li NMR spectra of the mixed crystals recorded at various temperatures suggested that the self-diffusion of Li+ions was excited in the highest-temperature solid phase. Based on these results, we have classified these mixed crystals as rotator crystals.