Single Crystal Growth of Double Honeycomb Lattice Superconductor Related Materials

双蜂窝晶格超导相关材料的单晶生长

• 批准号: 15340108
• 负责人: SHAMOTO Shin-ichi
• 金额: $ 10.3万
• 依托单位: Japan Atomic Energy Agency (2004-2005)Tohoku University (2003)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15340108/
• 关键词: Superconductivity; Double honeycomb lattice; Layered nitride

Structural study of double honeycomb lattice related materials such as Na_<0.9>Zr_2N_2S_<1.5>, Na_<0.85>Hf_2N_2S_<1.5>, Zr_2N_2S, and Hf_2N_2S has been performed by using X-ray powder diffraction data. As for Zr_2N_2S, and Hf_2N_2S, some reflection peaks such as -101 and 10-3 were broadened significantly, suggesting the intergrowth of α-M_2N_2S and β-M_2N_2S phases. This is a typical characteristic for two-dimensional compounds due to stacking faults. It indicates that the energy difference in stacking between α-M_2N_2S and β-M_2N_2S phases is very small. The structural analysis for these compounds has been carried out without these broad peaks. Based on the results, we estimated the band widths for these compounds. These estimated band widths were narrower than the band width of Na_<0.28>HfNCl, which had been the narrowest band width in any double honeycomb lattice compounds so far, suggesting large electron density of states. These band widths, however, do not correspond to our previous expectation. That is, the smaller the valence difference of two anions relative to the cation valence is, the narrower the band width is. The alkali metal intercalated HfNCl and ZrNCl superconductors exhibit wider band widths than the pristine compounds. So, the present double honeycomb lattice compounds may also show wider band widths after electron carrier doping. Carrier doped YOCl compounds have narrower band widths than the HfNCl and ZrNCl superconductors. It suggests that strong carrier localization due to the narrow band width plays an important role for the insulating property even with large number of carrier density. In these insulators, it is interesting to study the localized spin behavior with strong pairing interaction. This is the most important subject in the remaining research works about the present double honeycomb lattice compounds.

双蜂窝晶格相关材料的结构研究，例如Na_ <0.9> ZR_2N_2S_ <1.5>，Na__ <0.85> HF_2N_2S_2S_ <1.5>，ZR_2N_2S和HF_2N_2S，已使用X射线粉末衍射数据进行了执行。至于ZR_2N_2S和HF_2N_2S，某些反射峰（例如-101和10-3）显着拓宽，表明α-M_2N_2S和β-M_2N_2S阶段的增长。这是由于堆叠故障而导致二维化合物的典型特征。这表明α-M_2N_2S和β-M_2N_2S相之间堆叠的能量差很小。这些化合物的结构分析已经进行了，而没有这些宽峰。根据结果​​，我们估计了这些化合物的带宽。这些估计的带宽度比Na_ <0.28> HFNCL的带宽度要窄，这是到目前为止任何双蜂窝晶状体中最狭窄的带宽度，这表明状态的电子密度很大。但是，这些频段宽度与我们以前的期望不符。也就是说，相对于阳离子价相对于阳离子价的两个阴离子的价差越小，频带宽度越窄。碱金属插入的HFNCL和ZRNCL超导体暴露于原始化合物的较大带宽。因此，目前的双蜂窝晶格化合物也可能显示电子载体掺杂后更宽的带宽。与HFNCL和ZRNCL超导体相比，载体掺杂的YOCL化合物具有狭窄的带宽。它表明，即使大量的载体密度，由于狭窄的带宽而引起的强载体定位对于绝缘性质也起着重要作用。在这些绝缘子中，有趣的是研究局部旋转行为，具有强烈的配对相互作用。这是其余研究中最重要的主题，涉及目前的双蜂窝晶格化合物。

项目成果

Phonon anomaly on Na_xHfNCl superconductors with T_c=22K

T_c=22K 的 Na_xHfNCl 超导体上的声子异常

• 发表时间: 2004
• 期刊: J.Neutron Research 12・4
• 作者: Tomitsugu Taguchi;Naoki Igawa;Hiroyuki Yamamoto;Shin-ichi Shamoto;Shiro Jitsukawa;S.Shamoto et al.;S.Shamoto et al.;J.-H.Chung et al.;T.Yokoya et al.;S.Shamoto et al.
• 通讯作者: S.Shamoto et al.

Mater.Res.Soc.Symp.Proc.Q6

Mater.Res.Soc.Symp.Proc.Q6

• 发表时间: 2005
• 作者: Shin-ichi Shamoto;Noboru Yamada;Toshiyuki Matsunaga;Thomas Proffen;S.Shamoto et al.
• 通讯作者: S.Shamoto et al.

中性子散乱を用いた構造マッピング法

使用中子散射的结构映射方法

• 发表时间: 2004

Initial growth stage of a highly mismatched strontium film on a hydrogen-terminated silicon (III) surface

氢封端硅 (III) 表面上高度失配的锶薄膜的初始生长阶段

• 发表时间: 2006
• 期刊: Appl. Phys. Lett. 88
• 作者: Alexei A.Belik et al.;Alexei A.Belik et al.;Yusuto Machida et al.;H.Asaoka et al.
• 通讯作者: H.Asaoka et al.

Two-dimensional sodium fluctuation at high temperatures in a high-temperature thermoelectric material γ-Na_<0.7>CoO_2

高温热电材料γ-Na_<0.7>CoO_2在高温下的二维钠涨落

• 期刊: Jpn.J.Appl.Phys. (in press)
• 作者: Shin-ichi Shamoto;Yuki Hasegawa;Tsuyoshi Kajitani
• 通讯作者: Tsuyoshi Kajitani