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Title: Epitaxial NiCo 2 O 4 film as an emergent spintronic material: Magnetism and transport properties
The ferrimagnetic inverse spinel NiCo 2 O 4 has attracted extensive research interest for its versatile electrochemical properties, robust magnetic order, high conductivity, and fast spin dynamics, as well as its highly tunable nature due to the closely coupled charge, spin, orbital, lattice, and defect effects. Single-crystalline epitaxial thin films of NiCo 2 O 4 present a model system for elucidating the intrinsic physical properties and strong tunability, which are not viable in bulk single crystals. In this Perspective, we discuss the recent advances in epitaxial NiCo 2 O 4 thin films, focusing on understanding its unusual magnetic and transport properties in light of crystal structure and electronic structure. The perpendicular magnetic anisotropy in compressively strained NiCo 2 O 4 films is explained by considering the strong spin–lattice coupling, particularly on Co ions. The prominent effect of growth conditions reveals the complex interplay between the crystal structure, cation stoichiometry, valence state, and site occupancy. NiCo 2 O 4 thin films also exhibit various magnetotransport anomalies, including linear magnetoresistance and sign change in anomalous Hall effect, which illustrate the competing effects of band-intrinsic Berry phase and impurity scattering. The fundamental understanding of these phenomena will facilitate the functional design of NiCo 2 O 4 thin films for nanoscale spintronic applications.  more » « less
Award ID(s):
1710461 2044049
PAR ID:
10384106
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Journal of Applied Physics
Volume:
132
Issue:
2
ISSN:
0021-8979
Page Range / eLocation ID:
020901
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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