Very low 1/f barrier noise in sputtered MgO magnetic tunnel junctions with high tunneling magnetoresistance

Abstract

Low frequency 1/f barrier noise has been investigated in sputtered MgO magnetic tunnel junctions (MTJs) with a tunneling magnetoresistance ratio of up to 330% at room temperature. The lowest normalized noise parameter α of the tunnel barrier reaches 2.5 × 10−12–2.1 × 10−11 μm2, which is comparable to that found in MTJs with the MgO barrier grown by MBE or electron–beam evaporation. This normalized barrier noise is almost bias independent in the voltage range of up to ±1.2 V. The low noise level and high voltage stability may reflect the high quality of the sputtered MgO with a uniform distribution of defects in the MgO layer.

Operational Parameters for Sub-Nano Tesla Field Resolution of PHMR Sensors in Harsh Environments

“…Temperature dependence of the noise power spectral density and its detailed systematic analysis in MR sensors always provides a promising directive for its application even in harsh environments. In the literature, most of the noise analysis of MR sensors [ 16 , 21 , 32 , 33 , 34 , 35 , 36 ] has been done by comparing the experimental noise spectra with different numerical models, and the analyses deal with sensor noise performance at room temperature only, whereas very few systematic works have been carried out to investigate the total average noise as a function of temperature [ 37 ]. In the temperature dependence of the noise spectrum, an additional noise component appears due to the rise of temperature, generally caused by thermal drift.…”

Overview of Spintronic Sensors With Internet of Things for Smart Living

“…Therefore, the main roadblock to achieving ultrahigh SNR of TMR sensors is their relatively high noise level as compared to GMR sensors. Intrinsic noises in TMR sensors include thermal noise [51], shot noise [52,53], electronic 1/f noise [54,55], magnetic 1/f noise [56,57], and random telegraph noise (RTN) [58,59]. In the sensing region of a TMR sensor, the dominating noise source is normally the magnetic 1/f noise, which is essentially attributed to the thermally-driven magnetization fluctuation of the free FM layer.…”

Conductance enhancement due to interface magnons in electron-beam evaporated MgO magnetic tunnel junctions with CoFeB free layer deposited at different pressure

“…21,22 Therefore, verifying the existence of interface magnons and determining their energy is a research concern. [21][22][23][24] The growth conditions of MgO tunnel barrier in MTJs have a strong influence on TMR and noise parameters, [25][26][27][28] but there are fewer reports about the influence of the growth conditions on ferromagnetic electrode, which is possible to affect TMR and the tunneling process of MTJs. In this work, we have grown EB-MgO MTJs, with CoFeB free layer at different Ar pressures, to investigate the influence of CoFeB deposition conditions on the magnetoelectric transport properties.…”