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Title: Spin-torque diode with tunable sensitivity and bandwidth by out-of-plane magnetic field

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4953572· OSTI ID:22590755
; ;  [1]; ;  [2]
  1. Department of Electrical and Electronic Engineering, The University of Hong Kong (Hong Kong)
  2. Spintronics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

Spin-torque diodes based on nanosized magnetic tunnel junctions are novel microwave detectors with high sensitivity and wide frequency bandwidth. While previous reports mainly focus on improving the sensitivity, the approaches to extend the bandwidth are limited. This work experimentally demonstrates that through optimizing the orientation of the external magnetic field, wide bandwidth can be achieved while maintaining high sensitivity. The mechanism of the frequency- and sensitivity-tuning is investigated through analyzing the dependence of resonant frequency and DC voltage on the magnitude and the tilt angle of hard-plane magnetic field. The frequency dependence is qualitatively explicated by Kittel's ferromagnetic resonance model. The asymmetric resonant frequency at positive and negative magnetic field is verified by the numerical simulation considering the in-plane anisotropy. The DC voltage dependence is interpreted through evaluating the misalignment angle between the magnetization of the free layer and the reference layer. The tunability of the detector performance by the magnetic field angle is evaluated through characterizing the sensitivity and bandwidth under 3D magnetic field. The frequency bandwidth up to 9.8 GHz or maximum sensitivity up to 154 mV/mW (after impedance mismatch correction) can be achieved by tuning the angle of the applied magnetic field. The results show that the bandwidth and sensitivity can be controlled and adjusted through optimizing the orientation of the magnetic field for various applications and requirements.

OSTI ID:
22590755
Journal Information:
Applied Physics Letters, Vol. 108, Issue 23; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English