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Siušys A, Sadowski J, Sawicki M, Kret S, Wojciechowski T, Gas K, Szuszkiewicz W, Kaminska A, Story T. All-wurtzite (In,Ga)As-(Ga,Mn)As core-shell nanowires grown by molecular beam epitaxy. NANO LETTERS 2014; 14:4263-4272. [PMID: 24971488 DOI: 10.1021/nl500896d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Structural and magnetic properties of (In,Ga)As-(Ga,Mn)As core-shell nanowires grown by molecular beam epitaxy on GaAs(111)B substrate with gold catalyst have been investigated. (In,Ga)As core nanowires were grown at high temperature (500 °C) whereas (Ga,Mn)As shells were deposited on the {11̅00} side facets of the cores at much lower temperature (220 °C). High-resolution transmission electron microscopy images and high spectral resolution Raman scattering data show that both the cores and the shells of the nanowires have wurtzite crystalline structure. Scanning and transmission electron microscopy observations show smooth (Ga,Mn)As shells containing 5% of Mn epitaxially deposited on (In,Ga)As cores containing about 10% of In without any misfit dislocations at the core-shell interface. With the In content in the (In,Ga)As cores larger than 5% the (In,Ga)As lattice parameter is higher than that of (Ga,Mn)As and the shell is in the tensile strain state. Elaborated magnetic studies indicate the presence of ferromagnetic coupling in (Ga,Mn)As shells at the temperatures in excess of 33 K. This coupling is maintained only in separated mesoscopic volumes resulting in an overall superparamagnetic behavior which gets blocked below ∼ 17 K.
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Affiliation(s)
- Aloyzas Siušys
- Institute of Physics, Polish Academy of Sciences , al. Lotników 32/46, PL 02-668 Warszawa, Poland
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Sane P, Salonen E, Falck E, Repakova J, Tuomisto F, Holopainen JM, Vattulainen I. Probing Biomembranes with Positrons. J Phys Chem B 2009; 113:1810-2. [DOI: 10.1021/jp809308j] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Petri Sane
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Emppu Salonen
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Emma Falck
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Jarmila Repakova
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Filip Tuomisto
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Juha M. Holopainen
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Ilpo Vattulainen
- Department of Applied Physics, Helsinki University of Technology, Finland, Department of Ophthalmology, University of Helsinki, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Department of Physics, Tampere University of Technology, Tampere, Finland
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