Enhanced current-perpendicular-to-plane giant magnetoresistance effect in half-metallic NiMnSb based nanojunctions with multiple Ag spacers

Journal Article · Mon Jun 06 04:00:00 EDT 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4953403· OSTI ID:22590754

Wen, Zhenchao; Yamamoto, Tatsuya ^[1]; Kubota, Takahide; Takanashi, Koki ^[1]

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1. Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

Current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) heterostructure devices using half-metallic NiMnSb Heusler alloy electrodes with single, dual, and triple Ag spacers were fabricated. The NiMnSb alloy films and Ag spacers show (001) epitaxial growth in all CPP-GMR multilayer structures. The dual-spacer CPP-GMR nanojunction exhibited an enhanced CPP-GMR ratio of 11% (a change in the resistance-area product, ΔRA, of 3.9 mΩ μm{sup 2}) at room temperature, which is approximately twice (thrice) of 6% (1.3 mΩ μm{sup 2}) in the single-spacer device. The enhancement of the CPP-GMR effects in the dual-spacer devices could be attributed to improved interfacial spin asymmetry. Moreover, it was observed that the CPP-GMR ratios increased monotonically as the temperatures decreased. At 4.2 K, a CPP-GMR ratio of 41% (ΔRA = 10.5 mΩ μm{sup 2}) was achieved in the dual-spacer CPP-GMR device. This work indicates that multispacer structures provide an efficient enhancement of CPP-GMR effects in half-metallic material-based CPP-GMR systems.

• OSTI ID: 22590754
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 23 Vol. 108; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
EPITAXY
EQUIPMENT
FILMS
HEUSLER ALLOYS
LAYERS
MAGNETORESISTANCE
SPIN
TEMPERATURE RANGE 0273-0400 K