Advanced Magnetic Materials for Energy and Power Conversion Applications: Developments in Magnetic Materials for Sensors and Data Storage
Sponsored by: TMS Functional Materials Division, TMS: Magnetic Materials Committee
Program Organizers: Richard Beddingfield, GE; Daniel Salazar, BCMaterials; Alex Leary, NASA Glenn Research Center; Huseyin Ucar, California Polytechnic University,Pomona; Yongmei Jin, Michigan Technological University; Arcady Zhukov, University of the Basque Country

Tuesday 8:30 AM
March 16, 2021
Room: RM 25
Location: TMS2021 Virtual

Session Chair: Manh-Huong Phan, University of South Florida


8:30 AM  
Engineering of Magnetic Properties and Magnetoimpedance Effect of Fe-rich Microwires by Reversible and Irreversible Stress-annealing Anisotropy: Paula Corte-Leon; Valentina Zhukova1; Juan Maria Blanco2; Mihail Ipatov1; Arcady Zhukov3; 1Dept. Phys. Mater., Upv/Ehu; 2Dept. Appl. Phys., Univ. Basque Country; 3Dept. Phys. Mater., Upv/Ehu and Ikerbasque
    The magnetic properties of amorphous FeSiBC microwires have been thoroughly analyzed paying attention on the influence of annealing (under stress or without stress) on the GMI effect and magnetic properties of Fe-Si-B-C microwires. Stress annealing allows the induction of transverse magnetic anisotropy and the GMI effect improvement. This stress-annealing induced anisotropy depends on the stress-annealing conditions: annealing temperature, time and stress applied during the annealing and can be partially annealed out by subsequent furnace annealing. The reversibility of the stress-annealing induced anisotropy depends on the stress-annealing conditions: most of the transverse induced magnetic anisotropy obtained at high stresses values is irreversible. Stress-annealing followed by annealing without stress allows further GMI improvement. Coercivity, remanent magnetization, and magnetoimpedance ratio of FeSiBC microwires can be tuned by annealing conditions. Observed experimental results are discussed considering relaxation of internal stresses, compressive “back-stresses” arising after stress annealing and topological short range ordering.

8:50 AM  
Engineering of Magnetic Properties of Co- -rich Microwires by Post-processing : Lorena Gonzalez-Legarreta1; Valentina Zhukova1; Mihail Ipatov1; Paula Corte-Leon; Juan Blanco2; Arcady Zhukov3; 1Dept. Phys. Mater., Upv/Ehu; 2Dept. Appl. Phys., Univ. Basque Country; 3Dept. Phys. Mater., Upv/Ehu and Ikerbasque
     We studied effect of annealing conditions on GMI effect and DW dynamics of Co- rich Fe3.6Co69.2Ni1B12.5Si11Mo1.5C1.2 glass-coated microwires prepared by Tailor-Ulitovsky technique. A considerable coercivity, Hc, increase related to transformation of hysteresis loops from linear to rectangular after conventional annealing is observed. Despite that the stress-annealed microwires also present rectangular hysteresis loops, the Hc –values of the stress-annealed microwires are considerably lower than those annealed without stress. We observed an increase of GMI effect in annealed and stress-annealed microwires. In all the annealed and stress-annealed samples presenting rectangular hysteresis loops we observed the remagnetization by single DW propagation. The DW velocity, v, and DW mobility, S, depend on annealing conditions. At certain annealing conditions we observed v up to 4 km/s and S up to 29 (m2/s•A). Observed change of hysteresis loop discussed considering the modification of the magnetostriction coefficient after annealing, the stress relaxation and stress-induced magnetic anisotropy.

9:10 AM  
In Pursuit of Antiskyrmions for Energy-Efficient Spintronics: Structural and Magnetic Characterization of Uniaxial [Pt/Co]-based C2v Thin Films: Michael Kitcher1; Marc De Graef2; Vincent Sokalski2; 1 Carnegie Mellon University; 2Carnegie Mellon University
    Antiskyrmions and other unconventional magnetic objects are promising building blocks for energy-efficient spintronics. These spin textures can potentially be supported in low-symmetry ferromagnet–heavy metal (FM–HM) thin films where the Dresselhaus-type anisotropic Dzyaloshinskii-Moriya interaction (aDMI) arises at FM–HM interfaces. Here, we present C2v Ag/Pt/Co–based films which could exhibit aDMI and novel magnetic textures. For prototypical Ag(110)/Pt(110)/Co/Pt films grown epitaxially on Si(110) single crystal substrates, 2θ–ω X-ray diffraction and selected area electron diffraction revealed (10.0)-oriented hexagonal closed-packed (hcp) Co layers. Moreover, strong in-plane uniaxial anisotropy and crosstie domain walls were observed using alternating gradient field magnetometry and Lorentz transmission electron microscopy, respectively. To introduce DMI and explore its impact, we fabricated and characterized thinner symmetric and asymmetric Ag/Pt/[Co/Ni]x/Pt films. X-ray diffraction experiments suggest that the (10.0)-oriented hcp structure is preserved across Co/Ni layers. The structural and magnetic observations made are discussed along with their implications for aDMI.

9:30 AM  Invited
Kondo-like Behaviour and GMR Effect in Co-Cu Granular Alloys and Multilayers: Ricardo Lopez Anton1; Mihail Ipatov2; Juan Antonio Gonzalez1; Juan Pedro Andres1; Julian Gonzalez2; Valentina Zhukova2; Jakub Mino2; Arcady Zhukov2; 1Universidad de Castilla-La Mancha; 2University of the Basque Country
    Co-Cu Granular alloys and multilayers have attracted considerable attention since the beginning of 1990s, due to the existence of giant magnetoresistance (GMR) effect in those materials. Solubility of Co in Cu at room temperature is almost negligible but several preparation methods allow to obtain a metastable solid solution of a small quantity of Co in Cu. Additionally, it is also noteworthy the observation of Kondo-like resistivity minimums versus temperature in as-prepared and annealed Cu-Co microwires in the last years. Hence, we have studied these phenomena in granular alloys obtained by different methods (melt-spinning, sputtering and gas aggregation), checking also the effect of thermal treatments in their properties. Finally, we are currently studying if the Kondo-like minimum also appears in multilayer system (more appropriate for GMR applications) due to interdiffusion at the interfaces.

10:00 AM  Invited
Magnetic Real-time Tracking of Coronavirus Progress: A New Approach Utilizing Magnetic Sensor and Machine Learning: Manh-Huong Phan1; 1University of South Florida
    To limit the spread of Corona virus 2019 (COVID-19) and help doctors in clinical decision-making, the detection and real-time monitoring of their symptoms and growth at all (early, intermediate and severe) states is critical. Common symptoms of COVID-19 include: (i) shortness of breath or difficulty breathing, (ii) cough and (iii) fever. Current detectors provide limited information and possess lengthy processing time, or are physically contacted to patients. Therefore, there is an urgent need for developing contactless devices that enable early and fast detection of COVID-19 and track their growth rates in real time. In this talk, we show how to integrate an ultra-sensitive magnetic sensor technology with machine learning to develop an innovative, contactless diagnostic device that can sense the breathing symptoms of COVID-19 at multiple stages of disease progress and provide crucial information on the growth rate by patient of this deadly virus.

10:30 AM  Invited
Oxide Thin-film Electronics for the Front-end Conditioning of Flexible Magnetic Field Sensors: Niko Münzenrieder1; 1Free University of Bozen-Bolzano
    Unobtrusive magnetoreception can enable innovative applications in diverse scenario ranging from the interaction of humans with virtual objects to the controlled movement of microrobots. The required biocompatible magnetic senor systems have to be cheap and conform to the movement of tissue while providing excellent sensor performance. The key to realize such systems is the integration of magnetic sensors and condoning electronics on a single large-area plastic substrate. Optimized oxide thin-film transistors provide a technology platform which is not influenced by mechanical deformation or magnetic fields and can hence be used to boost the performance of magnetic sensors by front-end conditioning. Corresponding circuits provide gain up to 50 dB at operation voltages as low as 1.7 V while being bend to radii <5 mm. Fully flexible Co/Cu GMR sensors, Wheatstone bridges and amplifiers integrated on a polymer foil result in a 50 µm-thin conformal system with a 25 V/V/kOe sensitivity.

11:00 AM  
The Development of On-chip-coil Type GSR Sensor: Yoshinobu Honkura1; Shinpin Honkura1; Mizue Uemura1; 1Magnedesign Corp.
     Through applying GHz pulse current on the amorphous micro wire, we observed an increase in the coil voltage around the wire, and a sine function relationship between the coil voltage and the surrounding magnetic field as V=Vo sin(πH/2Hm)with almost no hysteresis. We assumed that the new performance must be caused by the rotation of electron spins and proposed to name it as GSR (GHz Spin Rotation) effect [1]. We developed the production technology to produce micro coils directly formed on the ASIC surface which make small size GSR sensor possible. We produced two types of on-chip-coil type GSR sensor which have a length of 0.12mm and 0.45mm and the coil turns of 14 and 66. These two types have larger sensitivity compared to that of the wire bonding type GSR sensor.[1] Y.Honkura, S.Honkura.: Sensors 20,1023 (2020)