International Journal of Applied Electromagnetics and Mechanics - Volume 73, issue 1

Authors: Carpentieri, Mario

Article Type: Editorial

DOI: 10.3233/JAE-239002

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 1-2, 2023

Authors: Goksal, Ilkin | Piskin, Hasan | Kocaman, Bayram | Akın, Kutay | Cay, Dogukan | Selvi, Ege | Karakas, Vedat | Lendinez, Sergi | Saglam, Hilal | Li, Yi | Pearson, John E. | Divan, Ralu | Zhang, Wei | Novosad, Valentine | Hoffmann, Axel | Ozatay, Ozhan

Article Type: Research Article

Abstract: Manipulation of antiferromagnetic sublattice orientations, a key challenge in spintronic device applications, requires unconventional methods such as current induced torques including Spin Transfer Torque (STT) and Spin-Orbit Torque (SOT). In order to observe the deviation of the Néel vector from the anisotropy axis, one of the simplest approaches is the electrical detection, whereby one monitors the change in resistance as a function of applied current. In this work, we have investigated the conditions under which an ultra-thin metallic antiferromagnet, Ir20 Mn80 becomes susceptible to SOT effects by studying antiferromagnetic layer structure and thickness dependence in antiferromagnetic metal (Ir20 Mn80 …)/heavy metal (Pt) superlattices. Our electrical measurements reveal that in bilayer structures there exists a shallow range of Ir20 Mn80 thicknesses (∼1–2 nm) for which SOT driven control of spins is apparent, whereas for lower thicknesses incomplete sublattice formation and for higher thicknesses improved thermal stability prohibits vulnerability to spin currents. Furthermore, in multilayers, structural changes in Ir20 Mn80 layer quenches local torques due to stronger (111) magnetocrystalline anisotropy. These results suggest that an exhaustive optimization of the antiferromagnet parameters is crucial for the successful deployment of spintronic devices. Show more

Keywords: Antiferromagnets, spin Hall effect, VNA-FMR, electronic transport

DOI: 10.3233/JAE-220298

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 3-13, 2023

Authors: Pérez, Santiago S. | Bedoya, Alessandro | Prócel, Luis Miguel | Taco, Ramiro

Article Type: Research Article

Abstract: Spin-transfer torque magnetic random-access memory (STT-MRAM) has been demonstrated to be a leading candidate for on-chip memory technology. In this work, double-barrier magnetic tunnel junction (DMTJ) is exploited to define STT-MRAMs at the circuit-level (i.e. at the bitcell level). The DMTJ-based bitcells are built from tunnel-FET technology and benchmarked against a calibrated 10 nm-FinFET technology model. STT-MRAM bitcells operate in the ultra-low voltage domain, and are evaluated in terms of energy-efficiency and area. Simulation results points out that the tunnel-FET based solution is the most energy-efficient alternative, in terms of energy-delay-product (EDP), when evaluated at the 6𝜎 corner. Quantitatively, when compared …against the FinFET-based design, the TFET-based bitcell exhibits 58% lower EDP, 40% better delay and 34% reduced writing energy. Finally, a leakage analysis was also carried out, showing that TFET-based STT-MRAM bitcells have lower leakage current as compared to the FinFET-based counterpart. Show more

Keywords: STT-MRAM, Tunnel FET, FinFET, Magnetic Tunnel Junction (MTJ), double-barrier MTJ (MTJ)

DOI: 10.3233/JAE-220300

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 15-24, 2023

Authors: Cutugno, Francesco | Mazza, Luciano | Azzerboni, Bruno | Meo, Andrea

Article Type: Research Article

Abstract: Spin-torque diode have shown great potentials and performance in many applicative fields, from microwave detectors to energy harvesters. In this work, we use micromagnetic simulations to study, at room temperature, a state-of-the-art non-resonant low-frequency-tail spin-torque diode in terms of dc output voltage as a function of the amplitude of an in-plane external field applied along different directions. We find that there exists a threshold value of the injected ac current that promotes a linear behavior of the output voltage of field down to the pT range, and we suggest exploiting such a behavior for the design of a magnetic field …sensor. Show more

Keywords: Magnetic tunnel junction, spin-torque diode, magnetic field sensor

DOI: 10.3233/JAE-220296

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 25-33, 2023

Authors: Ding, Hongchang | Li, Jinhong | Wei, Linchao | Zou, Xinhong

Article Type: Research Article

Abstract: To improve the speed and position detection accuracy of surface-mount permanent magnet synchronous motor (SPMSM) vector control and reduce unnecessary chattering of the system, this paper proposes a sensorless control strategy of SPMSM based on an adaptive sliding mode observer (ASMO) with optimized phase-locked loop (OPLL) structure. First, in order to overcome the chattering of system caused by discontinuous switching characteristic of signum function in conventional sliding mode observer (CSMO), a continuous saturation function is selected as the switching function. The ASMO adopts the system state-related adaptive gain function to adjust the switching gain value of the system in real …time, which overcomes the slow response speed or severe chattering of the system caused by the constant switching gain of CSMO. Second, to reduce the phase delay between the rotor position estimation value and the actual value caused by the adoption of low-pass filter (LPF) and the position estimation error caused by arctangent function method, an OPLL method is designed for accurate estimation of rotor position and speed. Finally, the effectiveness and feasibility of the proposed improved SMO algorithm is verified by simulation and experiments on an SPMSM with rated power of 2 kW. Show more

Keywords: Surface-mount permanent magnet synchronous motor (SPMSM), adaptive sliding mode observer (ASMO), sensorless control, adaptive gain function, optimized phase-locked loop (OPLL)

DOI: 10.3233/JAE-220258

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 35-55, 2023

Authors: Rocha-Gómez, Iván | Susarrey-Huerta, Orlando | Aguilar-Pérez, Arturo | Suárez-Calderón, Juan Carlos | Flores-Campos, Juan Alejandro | Desiderio-Maya, Daniela | Cruz-Deviana, Mario Ricardo | Cortés-Pérez, Jacinto | Torres-Cedillo, Sergio Guillermo | Reyes-Solís, Alberto

Article Type: Research Article

Abstract: This article presents an angular position control, based on the Gaussian function, of a Magneto-Rheological fluid disc brake (MR brake) driven by a DC motor. Our proposed control strategy is to apply a continuous magnetic flux density to the MR brake, which will be maximum when the proportional controller of the DC motor reaches the desired position to brake the hybrid device. The MR brake controller activates a braking torque that adopts the behavior of the Gaussian function instead of a pulsed braking torque as provided by other commonly used controllers (On-Off controllers). The response of the MR brake controller, …which is presented in a closed-loop feedback system, depends on the angular position error of the shaft and a tuning parameter representing the critical angular position at which the magnetic flux density, which is applied to the MR brake, reaches 60.65% of its maximum value. The advantage is to avoid knowing the dynamic parameters, such as the inertia of the mechanical device or its speed, and to reject these perturbations by a simple tuning parameter of the MR brake. To show the effectiveness of the proposed controller, the dynamic model of a slider-crank mechanism is considered. The results showed similar behavior as conventional controllers, where overshoot and oscillations were minimized. This behavior has been obtained in other research articles using controllers that require a greater amount of data processing. Show more

Keywords: Hybrid actuator, magneto-rheological, MR brake, Gaussian function, position control

DOI: 10.3233/JAE-220302

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 73, no. 1, pp. 57-71, 2023