Isotopic substitution of boron and carbon in superconducting diamond epilayers grown by MPCVD

0346854 - ÚJF 2011 RIV CH eng J - Článek v odborném periodiku
Achatz, P. - Omnès, F. - Ortega, L. - Marcenat, C. - Vacík, Jiří - Hnatowicz, Vladimír - Koster, U. - Jomard, F. - Bustarret, E.
Isotopic substitution of boron and carbon in superconducting diamond epilayers grown by MPCVD.
Diamond and Related Materials. Roč. 19, č. 7 (2010), s. 814-817. ISSN 0925-9635. E-ISSN 1879-0062
Grant CEP: GA AV ČR(CZ) KAN400480701
Výzkumný záměr: CEZ:AV0Z10480505
Klíčová slova: Isotopic effects * Vibrational properties * p-type doping
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 1.825, rok: 2010

Sets of heavily boron-doped {100}-oriented diamond epilayers have been grown by MPCVD from isotope-enriched gases such as (CH4)-C-13 and (B2H6)-B-10 or (CH4)-C-13 and naturally abundant (B2H6)-B-11, and the resulting concentration profiles of the various boron isotopes were measured by SIMS. In the particular case of the (CB)-C-13-B-10 set, the high absorption cross section of B-10 made neutron depth profiling possible for this element. The vibrational and superconducting properties of these epilayers were compared to those of films grown from gases containing the isotopes in their natural abundance. The critical temperature T-c values were found to be lower both in the (CB)-C-13-B-11 and (CB)-C-13-B-10 sets, as expected for a conventional pairing mechanism mediated by phonons. In good agreement with recent studies, the isotope-effect coefficient for Tc was found to be much higher than the classical 0.5 value. Various origins for this behaviour are suggested.
Trvalý link: http://hdl.handle.net/11104/0187769