The effect of Si addition in MgB₂thin films by hybrid physical–chemical vapor deposition using silane as the doping source

Abstract

We report the synthesis and characterization of silicon doped MgB 2 films fabricated by hybrid physical-chemical vapor deposition using silane as the doping source. Various amounts of Si up to 9% were added into MgB 2 thin films, which were epitaxially grown in situ on SiC. Compared with that of the undoped film, the superconducting transition temperature of the doped film does not show significant change; however the magnetic critical current density (J c ) has been increased. J c for the film with 5.0 at.% doping goes up to 2.7 × 10 5 A cm −2 for a 3 T perpendicular field. And the slope of the upper critical field curve for the doped film is slightly higher than that for the undoped MgB 2 film.

Influence of Electron-Beam Annealing Duration on MgB₂ Film Superconductivity

“…The primary problem to prepare MgB 2 superconducting devices is the preparation of high-quality MgB 2 thin films. Developed for nearly 11 years, several conventional thermal annealing methods, such as ex situ annealing methods [1][2][3][4], in situ annealing methods [5][6] and as-grown techniques [7][8][9][10][11][12][13], have been applied to the fabrication of MgB 2 films. But ex situ and in situ annealing method usually needs more than several minutes or even 10 min to finish the annealing process and their heating and cooling rates are slow.…”

“…It is not conducive to the generation of high-quality superconducting thin films. In spite of the outstanding superconducting properties of the MgB 2 films prepared by hybrid physical-chemical vapor deposition (HPCVD) [7][8][9][10], flammable, explosive, poisonous and expensive diborane (B2H6) gas must be used in the HPCVD method. In order to overcome or improve the shortcomings mentioned above, the effective electron beam annealing (EBA) method was first presented in June, 2011 by our group [14,15], in which the electron beam is used to irradiate Mg-B multilayer films to make Mg combine with B to form MgB 2 phase in a few seconds or sub-seconds without the use of the expensive B2H6, extra Mg vapor and argon gas.…”

Microwave Synthesis of Nano SiC Doping Mg(B_1-2x(SiC)_x)₂ Superconductor and Superconductivity

“…The discovery of binary intermetallic superconductor MgB 2 has received great attention because of it's relatively higher T c (39 K) and the better superconductivity characteristic, which make it a promising material to replace low-T c superconductors as well as for cryogen free operations [1,2]. During the past decade, many methods [3][4][5][6][7][8][9] and lots of doping agents [10][11][12][13][14][15][16][17][18][19][20][21][22][23] have been used to synthesize MgB 2 sample, and the critical characteristic of MgB 2 can be improved significantly by doping, especially nano SiC doping [23][24][25][26][27][28]. Microwave synthesis is a very promising preparation method for many materials because it is fast, clean and energy efficient.…”

Fabrication of superconducting magnesium diboride thin films by electron beam annealing

“…Third, there is thermal decomposition at high temperature in the synthesis of MgB 2 . To fabricate high quality superconducting MgB 2 thin films, several methods have been applied, including two-step in situ annealing techniques [3][4][5][6][7], two-step ex situ annealing techniques [7][8][9][10][11][12][13][14][15][16] and as-grown techniques [2,[17][18][19][20][21][22][23][24] such as hybrid physicalchemical vapor deposition (HPCVD) [2,[17][18][19][20][21][22][23]. In HPCVD B 2 H 6 is flammable, explosive, poisonous and expensive.…”