Investigation of electronic structure and electron conduction mechanism of InN

InN电子结构及电子传导机制研究

基本信息

批准号：
17560293
负责人：
INUSHIMA Takashi
金额：
$ 2.24万
依托单位：
TOKAI UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560293/
关键词：
Superconductivity of InN Fermi surface Electron Localization Critical current モット転移濃度

项目摘要

Temperature dependence of the resistivity of InN was investigated as a function of carrier density. The carrier density was changed from n_e=1.8x10^<18>cm^<-3> to 1.5x10^<19>cm^<-3> by Si doping. The InN investigated showed metallic conduction above 20 K. At lower temperatures there was a resistivity anomaly originating from carrier localization in the a-b plane, which was confirmed by the magnetoresistance at 0.5 K. The Shubnikov de-Haas oscillation showed that InN had a spherical Fermi surface and its radius increased according to the increase of ne when n_e<5x10^<18>cm^<-3>. In addition an oscillation corresponding to the constant carrier density of 4.5x10^<12>cm^<-2> was observed in the field applied perpendicular to the a-b plane. This oscillation showed an anomalous angle dependence on the magnetic field. Taking into account this density, we determined the critical carrier density of the Mott transition to be 2x10^<17>cm^<-3>. Anisotropy of localization was observed within the a-b plane, which indicates that the distribution of the electrons was not uniform in the a-b plane. From these results, an electronic structure at the fundamental absorption edge of InN grown on sapphire (0001) was presented.On the other hand, samples with carrier densities n_e as low as 4x10^<17>cm^<-3> show superconductivity with T_c= 0.47 K (midpoint). As in the layered cuprate high Tc superconductors, the vortex solid of InN is melted by thermal fluctuation and by the external magnetic field. The field dependence of the critical current J_c exhibits an exponential decay over a wide range of magnetic field, which is ascribed to the current tunneling through micro Josephson-junctions. We propose a mechanism where the anisotropy of J_c is related to the presence of In-In chains of finite length in the ab plane.

研究了INN电阻率的温度依赖性作为载体密度的函数。载体密度从n_e = 1.8x10^<18> cm^<-3>通过si掺杂而更改为1.5x10^<19> cm^<-3>。研究的酒店显示了高于20 K的金属传导。在较低的温度下，电阻率异常来自A-B平面中的载体定位，通过0.5 K处的磁倍率证实，Shubnikov de-Haas振荡表明，Inn Inn具有球形的Fermi表面及其半径及其半径为NEN ne ne ne_e^5x10^<5x10^<<5x10^<<5x10。另外，在垂直于A-B平面的场中观察到对应于4.5x10^<12> cm^<-2>恒定载体密度的振荡。该振荡显示出对磁场的异常依赖性。考虑到这种密度，我们确定Mott转换的临界载体密度为2x10^<17> cm^<-3>。在A-B平面内观察到定位的各向异性，这表明电子的分布在A-B平面中并不均匀。从这些结果中，呈现了蓝宝石在蓝宝石（0001）基本吸收边缘处的电子结构。另一方面，带有载体密度N_E的样品低至4x10^<17> cm^<-3>显示了具有T_C = 0.47 K（Midpoint）的超导性。就像在分层的丘比特高TC超导体中一样，Inn的涡流固体被热波动和外部磁场融化。临界电流J_C的场依赖性在各种磁场上表现出指数衰减，该磁场归因于通过Micro Josephson-Junctions的电流隧穿。我们提出了一种机制，其中J_C的各向异性与AB平面中有限长度的内链中存在有关。

项目成果

期刊论文数量（19）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Electronic structure of superconducting InN

DOI：
10.1016/j.stam.2006.05.009
发表时间：
2006-01-01
期刊：
SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS
影响因子：
5.5
作者：
Inushima, Takashi
通讯作者：
Inushima, Takashi

Superconductivity of InN

InN的超导性

DOI：
发表时间：
2006
期刊：
Physica Status Solidi A-Applications and Materials Science 203(1)
影响因子：
0
作者：
斎藤悠二;馬場俊彦;T.Inushima et al.
通讯作者：
T.Inushima et al.

Superconductivity of InN as an intrinsic property

InN 的超导性作为本征特性

DOI：
发表时间：
2007
期刊：
AIP Conf. Proc 893
影响因子：
0
作者：
T.Inushima;N.Kato;D.K.Maude;H.Lu;W.J.Schaff;R.Tauk;Y.Meziani;S.Ruffenach;O.Briot;B.Gil;H.Miwa;A.Yamamoto;D.Muto;Y.Nanishi
通讯作者：
Y.Nanishi

Evaluation of strain in AlN thin films grown on sapphire and 6H-SiC by metalorganic chemical vapor deposition

通过金属有机化学气相沉积法在蓝宝石和 6H-SiC 上生长的 AlN 薄膜的应变评估