Yokota Yuui, Kudo Tetsuo, Ohashi Yuji, Medvedev Andrey, Kurosawa Shunsuke, Kamada Kei, Yoshikawa Akira
New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-10, Aoba, Aramaki, Aoba-ku, Miyagi, Sendai 980-8579, Japan.
Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Miyagi, Sendai 980-8577, Japan.
Materials (Basel). 2015 Aug 26;8(9):5597-5605. doi: 10.3390/ma8095264.
Ca₃Nb(GaAl)₃Si₂O (CNGAS) single crystals with various Al concentrations were grown by a micro-pulling-down (µ-PD) method and their crystal structures, chemical compositions, crystallinities were investigated. CNGAS crystals with = 0.2, 0.4 and 0.6 indicated a single phase of langasite-type structure without any secondary phases. In contrast, the crystals with = 0.8 and 1 included some secondary phases in addition to the langasite-type phase. Lattice parameters, - and -axes lengths, of the langasite-type phase systematically decreased with an increase of Al concentration. The results of chemical composition analysis revealed that the actual Al concentrations in as-grown crystals were almost consistent with the nominal compositions. In addition, there was no large segregation of each cation along the growth direction.
采用微下拉（µ-PD）法生长了不同铝浓度的Ca₃Nb(GaAl)₃Si₂O（CNGAS）单晶，并对其晶体结构、化学成分和结晶度进行了研究。铝含量为0.2、0.4和0.6的CNGAS晶体呈现出单一的硅酸镧矿型结构相，没有任何次生相。相比之下，铝含量为0.8和1的晶体除了硅酸镧矿型相之外还包含一些次生相。硅酸镧矿型相的晶格参数、a轴和c轴长度随着铝浓度的增加而系统地减小。化学成分分析结果表明，生长态晶体中的实际铝浓度与标称成分几乎一致。此外，各阳离子沿生长方向没有大的偏析。
