ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Superconducting thin films (500–1000 A(ring) in thickness) of A15 V3Si have been grown on (111)Si substrates through molecular beam epitaxial techniques. V and Si are codeposited in a feedback-stabilized, 3:1 flux ratio from dual e-beam evaporators onto clean, heated Si substrates in an ultrahigh vacuum chamber. For the first time, the superconducting A15 V3Si phase is metastably fabricated directly on a crystalline Si substrate without the formation of thermodynamically favored Si-rich VxSiy phases. Our films exhibit superconductivity only within a narrow range of intermediate growth temperatures (centered near 400 °C), with an optimum Tc of 12.5 K. X-ray diffraction shows the superconducting films to be polycrystalline A15 V3Si. For slightly higher growth temperatures (≈530 °C), Auger profile, x-ray, and transmission electron microscopy measurements indicate the appearance of an intermediate layer of roughly 1:1 V:Si composition. Our observations demonstrate that a growth temperature near 400 °C results in successful nucleation of the superconducting A15 phase while minimizing solid phase reaction with the substrate during V3Si growth.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.100621
