2018 IEEE International Magnetic Conference (INTERMAG)最新文献

{"title":"Resistive switching in Pt/BiFeO3/SrRuO3/SrTiO3 heterostructures.","authors":"T. Wang, W. Cheng, C. Wang, H. Wang, Y. Hao, X. Miao","doi":"10.1109/INTMAG.2018.8508205","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508205","url":null,"abstract":"Abstract","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"44 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80653964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetically Controlled Light Manipulating Properties of Biogenic and Synthetic Guanine Crystals","authors":"H. Kashiwagi, M. Iwasaka, H. Asada, T. Koyanagi, K. Kishimoto","doi":"10.1109/INTMAG.2018.8508139","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508139","url":null,"abstract":"The magnetically controllable optical properties of guanine micro crystals derived from various species with camouflaging abilities offer promising prospects for future applications. Whereas comparable crystals have yet to be manufactured genetically, guanine crystals produced by chemical process are commercially available. In this study we examined the magnetic response and light reflecting properties of synthetic and biogenic guanine crystals under several hundred millitesla (mT) by means of real-time microscopy and spectroscopic measurement. Results show that synthetic crystals display controllable light manipulating properties comparable to those seen with biogenic crystals, and thus may also find possible application as micro-mirrors in optical instruments and MEMS.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"42 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88094529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin Reorientation, Magnetic Viscosity and Exchange Coupling Effects of the Nd-Ce-Fe-B Sintered Magnets Prepared by Singlemain-Phase and Dual-Main-Phase Alloy Methods","authors":"Yikun Fang, Z. Jiang, R. Han, Tao Liu, Minggang Zhu, Wei Li","doi":"10.1109/INTMAG.2018.8508040","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508040","url":null,"abstract":"Temperature dependence of magnetic properties of 20%-Ce substitution Nd-Ce-Fe-B as-sintered and tempering magnets was investigated systematically. These magnets were fabricated by single-main-phase (SMP) and double-main-phase (DMP) methods, respectively. The DMP as-sintered magnet exhibits the highest Ms (~185emu/g) and Mr (~133 emu/g) among these specimens at 60K. Microstructural investigation shows that the component of DMP specimens varies in a large range; part of main phase is Ce-lean. Magnetic analysis indicates DMP tempering specimen has best temperature coefficient of remanent and coercivity over the measurement temperature range. The ac susceptibility investigation indicates the spin reorientation temperature increases from 80K for SMP specimens to 90K for DMP specimens, giving rise to the positive remanent temperature coefficient bellow 120K. The magnetic viscosity parameter of DMP as-sintered specimen is 4.23 emu/(g·s), the highest among the specimens, while DMP tempering specimen is only 2.07 emu/(g·s), indicating that tempering reduces magnetic viscosity of DMP specimens. The Henkle plots results indicate tempering reduce exchange coupling interaction between grains.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"61 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83145612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Skyrmion Dynamics in Wedge-shaped Nanotrack and Its Potential Applications.","authors":"X. Chen, W. Kang, D. Zhu, X. Zhang, Y. Zhang, Y. Zhou, W. Zhao","doi":"10.1109/INTMAG.2018.8508208","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508208","url":null,"abstract":"Magnetic skyrmions are swirling topological configuration [1], mostly induced by chiral exchange interactions between atomic spins in non-centrosymmetric magnetic bulks or in thin films with broken inversion symmetry. With the rapid advances made in this field [2–3], the development of skyrmion-based spintronics holds promise for future applications owing to the topological nature, nanoscale size, and ultralow current density for motion. Furthermore, the standby energy consumption and heat generation during the processing and transportation of information can be efficiently reduced thanks to the nonvolatility. In this abstract, we present firstly our investigations on skyrmion dynamics in terms of size, velocity, energy, stability in a wedge-shaped nanotrack via micromagnetic and theoretical studies [4]. We find some interesting results compared to previous research. For example, the size of a skyrmion decreases as the nanotrack width decreases because of the compression by the nanotrack edge (see Fig. 1a), thus this property can be harnessed to adjust the dimension of skyrmions to acheive ultra-dense storage in racetrack memory [5]. Inspired by the findings in wedge-shaped nanotracks, we draw a conclusion about the tradeoff between the nanotrack width (storage density) and the skyrmion motion velocity (data access speed) by further analyzing the skyrmion dynamics in parallel nanotracks (see Fig. 1b). Our results may provide guidelines in designing skyrmion racetrack memory and other related skyrmionic applications. We also model a novel compact neuron device based on this wedge-shaped nanotrack. Under the coaction of the exciting current pulse and the repulsive force exerted by the edge of the nanotrack, the dynamic behavior of the proposed skyrmionic artificial neuron device corresponds to the leaky-integrate-fire (LIF) spiking function of a biological neuron (see Fig. 2). We believe that our study makes a significant step because such a compact artificial neuron can enable energy-efficient and high-density implementation of neuromorphic computing hardware [6].","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"5 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85474723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual Mode Dual Stator Wound Rotor Synchronous Machine for Variable Speed Applications.","authors":"A. Hussain, Muhammad Saad Ayub, T. Yazdan, B. Kwon","doi":"10.1109/INTMAG.2018.8508493","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508493","url":null,"abstract":"Electric vehicles and hybrid electric vehicles are being developed as a means to extenuate the environmental concerns. Permanent magnet (PM) machines have been used for such applications due to their high torque density, robust structure and no need for an external excitation system. However, the limited supply and increasing price of PM material create a need to search the alternative solutions such as the brushless wound rotor synchronous machines (BL-WRSM). Several brushless topologies for WRSMs have been presented in [1- 3]. In [1] and [2], the brushless operation of WRSM is achieved by utilizing sub-harmonic and third harmonic components of stator MMF, respectively. In [3], the sub-harmonic component of stator MMF is generated by dividing the stator winding into two sets of series connected windings, which are then supplied through a single inverter. In the brushless topologies, the stator current is the only source of excitation and the field current is induced from the harmonic component of MMF. When the machine operates below the rated speed, the induction process slows down and the magnitude of the field current is gradually decreased with the decrease in the speed of the machine. Therefore, the torque in the constant torque region cannot be maintained constant by the BL-WRSM. However, at or above the rated speed these machines work properly. In this paper, a dual mode dual stator wound rotor synchronous machine (DMDS-WRSM) for variable speed applications is proposed. Through the dual mode (DM) machine operation, the constant torque and the constant power are achieved in the constant torque and constant power region, respectively. However, the dual stator design has been chosen to improve the torque density of the machine as compared to the torque density of the single stator BL-WRSM presented in [3]. A 2-D finite element analysis is performed to validate the proposed DMDS-WRSM.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"170 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74159299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Observation of Sub-100 nm Spin Wave Propagation in Magnonic Wave-Guides","authors":"N. Träger, P. Gruszecki, F. Lisiecki, J. Förster, M. Weigand, P. Kuświk, J. Dubowik, G. Schütz, M. Krawczyk, J. Gräfe","doi":"10.1109/INTMAG.2018.8508640","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508640","url":null,"abstract":"In magnonics research, capabilities of data processing mediated by spin waves are of current interest for beyond-CMOS data processing technologies, promising non-Boolean computing algorithms or majority gates substituting several tens of CMOS transistors and making this an exciting candidate for next level computing [1–3]. Furthermore, due to the short wavelength of magnons at technological relevant radio frequencies, smaller structural elements and, thus, miniaturization of various devices will be possible [4]. However, for magnonic logic operations, reliable spin wave guides are indispensable. Here, we use scanning transmission x-ray microscopy (STXM, MAXYMUS@BESSY II) with magnetic contrast and a spatial and temporal resolution of 18 nm and 35 ps respectively to investigate such wave-guides. These were structured in 50 nm thin Py stripes with a width of 350, 700 or 1400 nm and a length of 11 μm. A coplanar waveguide (Cr/Cu/Al) was deposited on top to allow RF excitation of spin waves in the structures (cf.Fig. 1 for a schematic sketch and a microscopy image). After time-domain STXM acquisition of the magnetization movie under RF excitation, a temporal Fourier transformation is performed to gain the spatial distribution of the spin wave amplitude and phase. This is shown exemplary in Fig. 2(a) for a 1400 nm wide Py stripe under CW excitation at 4.6 GHz and in an external field of 15 mT applied parallel to the long axis of the wave-guide (BV configuration). One can clearly observe that highly directed spin waves emerge from the edges of the wave-guide [5]. Due to the emission from both edges, a standing wave forms along the Py stripe. To quantify the spinwave properties a spatial Fourier transformation was performed to derive the k-space distribution of the wave vectors, which is shown in Fig. 2(b). Here, two components stand out beside the DC peak in the center showing that these microstructures act as multimode wave-guide. The first spin-wave modes has a wave vector k1 = 4.7 μm-1, which corresponds to a wavelength of $lambda _{1} quad =210$ nm, and a second mode with a k-vector $mathrm {k}_{2} quad = 10.5 mu mathrm {m}^{-1}$ is visible. Thus, we are able to microscopically observe a spin-wave with a wavelength of $lambda _{2} =95$ nm and experimentally break through the 100 nm limit. Furthermore, we have performed a systematic variation of excitation frequency and applied external field for the different wave-guide widths. By varying these parameters, the wavelength as well as the propagation direction are tuned, indicating also diagonal and curved propagating of spin-waves that resembles the propagation of light in a graded-index fiber. Additionally, we recreated a data transmission scenario by using a Burst excitation scheme, i.e. four periods of RF excitation followed by a free decay time. Thereby, simultaneously excited multiple modes are carried by the Py wave-guide. They are interleaving without disrupting each other, further confirming ","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"47 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86063383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a High Power density Halbach BLDC Motor for Electric Vehicle Propulsion.","authors":"V. R. Bommadevara","doi":"10.1109/INTMAG.2018.8508741","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508741","url":null,"abstract":"Electric vehicles (EV) are the need of the day for future transportation. The electric drives used for vehicle propulsion need to be highly efficient and high power dense to improve the performance of EVs and make them competent in transportation applications. In the similar lines this paper proposes a Radial Flux BLDC motor with surface magnet rotor with a halbach array. The complete design of motor is carried out, nonlinear magnetic analysis carried out and arrived at performance characteristics. The proposed topology is compared with conventional BLDC motor and found an increment of 20% in torque density. The hardware is realized and tested for its performance","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"15 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84315387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scaling of All-Optical Switching to Nanometer Dimensions.","authors":"A. ElGhazaly, C. Lambert, B. Tran, A. Pattabi, J. Gorchon, S. Salahuddin, H. Wong, J. Bokor","doi":"10.1109/INTMAG.2018.8508154","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508154","url":null,"abstract":"Here, we first demonstrate helicity-independent all-optical switching in GdCo, a material chosen for stronger perpendicular magnetic anisotropy (PMA) than GdFeCo but with similar ferrimagnetic properties; furthermore, we achieve reliable AOS down to 200 nm diameters. The greater challenge to scaling was maintaining the perpendicular magnetic anisotropy for smaller dot dimensions, as was found to be a challenge in. While ion milling is a common method for patterning MTJ pillars for MRAM, it was found to destroy the integrity of the PMA. Instead, a lift-off process with electron -beam lithography was used to pattern the nanodots, ranging in size from 15 pm down to 50 nm, into arrays. Each dot size of diameter d was arrayed with a pitch of 3d in a25 pm x 25 pm square region. The pitch was chosen to be large enough to prevent magnetistatic coupling between the dots, while simultaneously allowing a high areal density of the dots for maximum magnetic signal during subsequent optical measurements.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"24 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83246834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traffic Flow and Vehicle Speed Measurements using Anisotropic Magnetoresistive (AMR) Sensors","authors":"B. Santoso, Bo Yang, C. Ong, Zhi-Min Yuan","doi":"10.1109/INTMAG.2018.8508869","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508869","url":null,"abstract":"Vehicles with ferrous material composition change the distribution of uniform earth magnetic field around them. The anisotropic magneto-resistive (AMR) sensor usually has magnetic field detection range within ±10 Oe, which is suitable to detect the earth magnetic field at 0.25~0.65 Oe as a low cost solution. The AMR sensor is able to sense the vehicle induced magnetic field change and can be utilized as vehicle detection sensor. This work uses two AMR sensor nodes to measure the vehicle velocity on the road. Signal processing is applied to remove noise and to get clean signal for precise speed calculation. The vehicle speed measured by AMR sensor is validated by a high speed camera at 250 fps. The AMR sensor at low cost and low power is a promising vehicle speed sensor for traffic flow and density management in the intelligent transport system.","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"55 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78822204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MgO-based Magnetoresistive Biosensor for Magnetically labeled Cells Detection.","authors":"S. Amara, R. Bu, M. Alawein, H. Fariborzi","doi":"10.1109/INTMAG.2018.8508528","DOIUrl":"https://doi.org/10.1109/INTMAG.2018.8508528","url":null,"abstract":"Since the discovery of the giant magnetoresistance (GMR), many spintronic devices have been developed and used in various applications such as information storage and automotive industry. Nowadays, increasing research in the field of spintronics and its application in the development of magnetoresistive (MR) biomolecular and biomedical platforms is giving rise to a new family of biomedical sensors [1]–[3]. Magnetic tunnel junctions (MTJ), based on MgO barriers, are promising magnetic field sensor solutions in the framework of electronic components integration and miniaturization. MgO-based MTJs show superior sensitivity for the detection of small magnetic fields needed in many industrial and biomedical applications. MgO-based MR sensors have been integrated for biological applications, such as biochips. The concept, explained in [4] and [5], relies on the capability of the sensor for detection of the fringe field generated by magnetized nano/microparticles attached to biomolecules. In this work, we aim to implement MgO-based MR biosensors for measurement of the flux of magnetically labeled cells. As a representative schematic, the biochip in figure 1.a shows different components of the MR biosensor. Figure 1.b illustrates the concept with superparamagnetic beads. As shown, a magnetic bead above the sensor will be magnetized by the magnetic field generated by the current in the gold strip. The stray field of the bead can be sensed by the magnetic field sensor, if the magnetic bead is within its sensing space. When a larger number of magnetic beads labeling the cells are mobilized inside the micro-tube, a larger signal will be observed. We should mention that the manipulation of these particles and biomolecules requires handling fluidic samples. Moreover, the labeling particles should be handled under minimum aggregation, preferably in a paramagnetic state. We designed and fabricated MgO-based MR sensors presented in figure 2.a. Each sensor consists of 1200 elliptic 16*8 mm 2 pillars in series. MTJ multilayer films were deposited using a magnetron sputtering system (Singulus Rotaris) on thermally oxidized Si wafers. The MTJ stack used in this study had the following layer structure: (thicknesses in nanometers) Si/SiO2/(3)Ru /(8) Ta /(3)Ru(8) Ta /(3) Ru /(8)MnIr $_{20} /(2.3)$ Co 70 Fe $_{30} /(0.85)$ Ru / (2.4) Co 60 Fe 20B20 ferromagnetic pinned layer)/ (1.53) MgO / (1.45) Co 60 Fe 20B20 magnetic free layer)/(3)Ru /(8) Ta. MTJ stack was patterned into micron-sized elliptical devices using standard optical lithography and ion milling. A 150-nm-thick gold layer was deposited over the junction area and patterned into low-resistance electrical contacts for each MTJ. After patterning, the samples were annealed at $360 ^{circ}mathrm {C}$ for 2 h at $1.10 ^{-6}$ Torr in an applied field of 8 kOe. The magnetoresistance properties of the MR sensors were measured at room temperature in air by a conventional DC four-probe method and current driven Helmholtz ","PeriodicalId":6571,"journal":{"name":"2018 IEEE International Magnetic Conference (INTERMAG)","volume":"63 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2018-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80745593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}