Enhanced electron-phonon coupling in NbB2 by nanoscaling the grain size

被引：2

作者：

Bao, Lihong ^{[1
,2
]}

Yang, Fan ^{[1
]}

Tegus, O. ^{[1
]}

Huang, Ying Kai ^{[2
]}

Leng, Hua Qian ^{[2
]}

de Visser, Anne ^{[2
]}

机构：

[1] Inner Mongolia Normal Univ, Inner Mongolia Key Lab Phys & Chem Funct Mat, Hohhot 010022, Peoples R China

[2] Univ Amsterdam, Van der Waals Zeeman Inst, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands

来源：

MATERIALS CHARACTERIZATION | 2019年 / 150卷

基金：

中国国家自然科学基金;

关键词：

Nanocrystalline; NbB2; Grain size effects; Electron-phonon coupling; THERMODYNAMIC PROPERTIES; 1ST-PRINCIPLES; MICROSTRUCTURE; NANOPARTICLES; PRESSURE; CRYSTAL; TEMPERATURE; REDUCTION; DIBORIDE; BORIDES;

D O I：

10.1016/j.matchar.2019.02.003

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Nanocrystalline NbB2 powder has been synthesized via a single step solid-state reaction of precursor materials Nb2O5 and NaBH4. Phase composition, grain morphology, microstructure, phonon vibrations and superconducting properties were investigated by XRD, FESEM, HRTEM, Raman spectroscopy and PPMS. The results show that the grain size of nanocrystalline NbB2 is very sensitive to the reaction temperature and easy to aggregate to form micron scale of non-morphology powders. A systematic increase of the electron-phonon coupling constant with the nanoscaling grain size is observed, which we explain in terms of crystal defects and phonon vibrations. The zero-temperature critical fields, H-c1 (0) and H-c2 (0), have been estimated at 85 Oe and 7200 Oe, respectively, and the Ginzburg-Landau parameter kappa is 5.1, confirming that NbB2 is a type-II superconductor.

引用

页码：13 / 21

页数：9

共 53 条

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