Kimura Kenta, Sera Masakazu, Kimura Tsuyoshi
Division of Materials Physics, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.
Inorg Chem. 2016 Feb 1;55(3):1002-4. doi: 10.1021/acs.inorgchem.5b02622. Epub 2016 Jan 14.
Single crystals of two novel tetragonal chiral materials, A(TiO)Cu4(PO4)4 (A = Ba, Sr), were grown from Na2Mo2O7 flux, and their crystal and chiral domain structures were characterized. Polarized-light microscopy studies of the chiral domain structures in the crystals show that Ba(TiO)Cu4(PO4)4 mostly hosts a multidomain state, while a monodomain state predominantly appears in Sr(TiO)Cu4(PO4)4. To explain this striking difference, we quantified the chirality strength of these materials by comparing atomic positions in the chiral and nearest-achiral crystal structures, revealing larger chirality strength in Sr(TiO)Cu4(PO4)4 than in Ba(TiO)Cu4(PO4)4. Our proposed mechanisms linking the chirality strength and domain formation can account for the different occurrence frequency of chiral domains in this system.
两种新型四方手性材料A(TiO)Cu4(PO4)4（A = Ba，Sr）的单晶通过Na2Mo2O7助熔剂生长而成，并对其晶体和手性畴结构进行了表征。对晶体中手性畴结构的偏光显微镜研究表明，Ba(TiO)Cu4(PO4)4主要呈现多畴状态，而Sr(TiO)Cu4(PO4)4中主要出现单畴状态。为了解释这一显著差异，我们通过比较手性和最近的非手性晶体结构中的原子位置，对这些材料的手性强度进行了量化，结果表明Sr(TiO)Cu4(PO4)4中的手性强度大于Ba(TiO)Cu4(PO4)4中的手性强度。我们提出的将手性强度与畴形成联系起来的机制可以解释该系统中手性畴出现频率的差异。
