Maafa I, Hajjar-Garreau S, Jaafar R, Berling D, Pirri C, Mehdaoui A, Denys E, Florentin A, Garreau G. Room-temperature ferromagnetism of all-epitaxial β-Fe-Ge/diamond-Ge/β-Fe-Ge trilayers.
J Phys Condens Matter 2013;
25:256007. [PMID:
23740804 DOI:
10.1088/0953-8984/25/25/256007]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report on the first all-epitaxial ferromagnet/inorganic semiconductor/ferromagnet hybrid heterostructure that exhibits (i) a Ge barrier of diamond crystal structure, (ii) room-temperature ferromagnetic electrodes and (iii) very smooth interfaces. Both bottom- and top-Fe-Ge electrodes exhibit tiny in-plane magnetic anisotropies dominated by a magnetocrystalline contribution of six-fold symmetry originating from the hexagonal symmetry of the B82 (Ni2In) β-Fe-Ge phase. A key result is the absence of any magnetic coupling between these soft-magnetic electrodes for Ge barrier thickness as low as ~2.5 nm, which allows us to easily tune the parallel and antiparallel magnetic alignments by applying suitably small magnetic fields. This confirms the beneficial use of H-surfactant in order to drastically reduce the roughness of the Ge barrier, as revealed by our scanning tunneling microscopy and transmission electron microscopy measurements. This new all-epitaxial ferromagnet/semiconductor hybrid system appears, therefore, to be a promising candidate for the realization of magnetic tunnel junctions with a single crystal semiconductor barrier that are fully compatible with Si-based technology.
Collapse