Dislocation structures, interfacing, and magnetism in the L1₀- MnGa on η_⊥ - Mn₃N₂ bilayer

Journal Article · Wed May 01 00:00:00 EDT 2019 · Journal of Vacuum Science and Technology A

DOI:https://doi.org/10.1116/1.5081960· OSTI ID:1609754

Corbett, J. P. ^[1]; Guerrero-Sanchez, J. ^[2]; Gallagher, J. C. ^[3]; Mandru, A. -O. ^[1]; Richard, A. L. ^[1]; Ingram, D. C. ^[1]; Yang, F. ^[3]; Takeuchi, N. ^[2]; Smith, A. R. ^[1]

---

1. Ohio Univ., Athens, OH (United States)
2. Univ. Nacional Autónoma de México, Ensenada Baja, CA (Mexico)
3. The Ohio State Univ., Columbus, OH (United States)

Ferromagnetic L1₀-MnGa was grown by molecular beam epitaxy under ultrahigh vacuum conditions to a 73 ± 5 nm thickness atop of 50 ± 5 nm thick molecular beam epitaxy grown antiferromagnetic η_⊥-Mn₃N₂ on a MgO(001) substrate. The MnGa grew along the c-axis with an out-of-plane spacing of c = 3.71 ± 0.01 Å and a relaxed in-plane spacing of a = 4.00 ± 0.05 °A measured with X-ray diffraction and reflection high-energy electron diffraction respectively. Williamson-Hall analysis revealed 67 ± 17 nm tall columnar grains with a residual stress of 2.40 ± 0.26 (×10^-3). A radial distribution plot of screw dislocations observed in scanning tunneling microscopy images found an in-plane coherence length of 15 ± 5 nm. Reflection high-energy electron diffraction analysis of the in-plane lattice spacing during growth reveals a critical thickness of 1.05 ± 0.65 nm for the MnGa, by which the MnGa film relaxes by incorporating dislocations of both edge and screw type. Vibrating sample magnetometry was employed to obtain the magnetic properties of the bilayer system. It is found that the dislocation density plays a significant role in understanding the measured moment per unit cell, where a large dislocation density lowers the moment per unit cell significantly due to chemical layering disorder. Finally, this finding is important for materials development of large saturation magnetization.

• Research Organization: Ohio Univ., Athens, OH (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division
• Grant/Contract Number: FG02-06ER46317; SC0001304
• OSTI ID: 1609754
• Alternate ID(s): OSTI ID: 1505010
• Journal Information: Journal of Vacuum Science and Technology A, Vol. 37, Issue 3; ISSN 0734-2101
• Publisher: American Vacuum Society / AIP
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Materials Science
Physics