Unravelling the local crystallographic structure of ferromagnetic $$\gamma '$$ γ ′ - $$\hbox {Ga}_y \hbox {Fe}_{4-y}$$ Ga y Fe 4 - y N nanocrystals embedded in GaN

Autor: Andrea Navarro-Quezada, Katarzyna Gas, Anna Spindlberger, Fahim Karimi, Maciej Sawicki, Gianluca Ciatto, Alberta Bonanni
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Scientific Reports, Vol 11, Iss 1, Pp 1-9 (2021)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-021-82380-4
Popis: Abstract In the Fe-doped GaN phase-separated magnetic semiconductor Ga $$\delta $$ δ FeN, the presence of embedded $$\gamma '$$ γ ′ - $$\hbox {Ga}_y \hbox {Fe}_{4-y}$$ Ga y Fe 4 - y N nanocrystals determines the magnetic properties of the system. Here, through a combination of anomalous X-ray diffraction and diffraction anomalous fine structure, the local structure of Ga in self-assembled face-centered cubic (fcc) $$\gamma '$$ γ ′ - $$\hbox {Ga}_y \hbox {Fe}_{4-y}$$ Ga y Fe 4 - y N nanocrystals embedded in wurtzite GaN thin layers is investigated in order to shed light onto the correlation between fabrication parameters, local structural arrangement and overall magnetic properties of the material system. It is found, that by adjusting the growth parameters and thus, the crystallographic surroundings, the Ga atoms can be induced to incorporate into 3c positions at the faces of the fcc crystal lattice, reaching a maximum occupancy of 30%. The magnetic response of the embedded nanocrystals is ferromagnetic with Curie temperature increasing from 450 to 500 K with the Ga occupation. These results demonstrate the outstanding potential of the employed experimental protocol for unravelling the local structure of magnetic multi-phase systems, even when embedded in a matrix containing the same element under investigation.
Databáze: Directory of Open Access Journals
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