Antiferromagnetic domain wall motion driven by spinorbit torques takayuki shiino,1, sehyeok oh,2, paul m. Robust antiferromagnetic coupling in hardsoft bimagnetic. A beam of slow neutrons passing through antiferromagnetic material interacts with the magnetic ions of the substance and is scattered. Reorientational transition of the magnetic anisotropy and antiferromagnetic coupling of cocr001 superlattices. The result is a very timely monograph for solid state physicists and chemists, materials scientists, electrical engineers, physicists in industry. The intraplane coupling is antiferromagnetic while interplane coupling is.
The temperature dependence of the v and co 2pcore xray absorption spectra 2p xas in vf3 and cof2, respectively, are discussed on the basis of an atomic model including multipletsplitting, 3d. The exact determination of what j is for any given system is usually impossible to find exactly. Spinphonon coupling in antiferromagnetic nickel oxide. They are widely applied for technological applications, such as giant magnetoresistance gmr using antiferromagnetic coupling at interface of the magnetic thin film multilayer in order to increase areal density from 15 gbin2 up to 1070 gbin2 1. Antiferromagnetic article about antiferromagnetic by the. We focus on the antiferromagnetic insulators whose lowenergy effective model possesses a topological term called the. Pdf from antiferromagnetic to ferromagnetic coupling for.
The free energy fo is a nonanalytical function of h for. The robust antiferromagnetic coupling is stabilized by a superexchange. Signproblemfree quantum monte carlo of the onset of. Evidence for antiferromagnetic coupling of fe layers across cr interlayers journal of applied physics 61, 3750 1987. Ferromagnetic ordering is achieved for fe wires deposited on this template. Magnetic properties of antiferromagnetic oxide materials. Dec 17, 20 magnetic nanoparticles are studied for their potential use in nanomagnetic devices. Mechanism and control of antiferromagnetic coupling in fefe3o4. Thompson,3 lapo bogani,1 fernando luis,4 stephen j. A robust soliton ratchet using combined antiferromagnetic and ferromagnetic interlayer couplings. The antiferromagnetic coupling was crucial for the discovery that the resistance of metallic magnetic multilayers depends on the relative orientation of the magnetization in adjacent layers. Pdf we report an advanced organic spininterface architecture with magnetic. Exchange coupling of co and fe on antiferromagnetic nio.
Antiferromagnetic af interlayer exchange coupling between magnetic layers separated by metallic or insulating spacers is a basic effect for spintronics. Strain dependence of antiferromagnetic interface coupling. Kiyoshi nogi, in nanoparticle technology handbook second edition, 2012. Antiferromagnetic coupling in codoped zns springerlink. Antiferromagnetic coupling in ferromagneticferrimagnetic. The invention uses an upper and lower magnetic layer of a laminated magnetic layer structure that includes an af spacer layer that results in weak antiferromagnetic coupling of the magnetic layers that is insufficient to cause either of the layers to switch so that the magnetic orientations of the two ferromagnetic layers remain parallel. Ferromagnetic and antiferromagnetic coupling of spin molecular. Antiferromagnetic interfacial coupling and giant magnetic. Neutrons have no electric charge but possess a magnetic moment. Laird1, 1department of materials, university of oxford, oxford ox1. Haney,3 seowon lee,4 gyungchoon go,4 byongguk park,1, y and kyungjin lee2,4,5, z 1department of materials science and engineering, kaist, daejeon 34141, korea 2department of nanosemiconductor and engineering, korea university, seoul 02841, korea 3center for nanoscale science and. In order to highlight the contribution, we subtracted the.
Strong coupling of microwave photons to antiferromagnetic fluctuations in an organic magnet matthias mergenthaler,1,2, junjie liu,1 jennifer j. By solving the landaulifshitzgilbert equation in the presence of the. Cayleytree ising model with antiferromagnetic nearest. Magnetization behavior can be understood to be due to defectinduced ferromagnetism.
They are widely applied for technological applications, such as giant magnetoresistance gmr using antiferromagnetic coupling at interface of the magnetic thin film multilayer in order to increase areal density from 1. Pickett department of physics, university of california, davis ca 956168677 dated. Study of antiferromagnetic coupling by ferromagnetic resonance fmr article pdf available in journal of magnetism and magnetic materials 17623. Computational details for the dft modeling and orbital magnetization pdf. We study theoretically spin dynamics in threedimensional antiferromagnetic insulators with spinorbit coupling. Dec 21, 2012 the quantum theory of antiferromagnetism in metals is necessary for our understanding of numerous intermetallic compounds of widespread interest. This is, like ferromagnetism and ferrimagnetism, a manifestation of ordered magnetism generally, antiferromagnetic order may exist at sufficiently low. Shan surface physics laboratory state key laboratory and department of physics, fudan university, shanghai 200433, china j. We have found that the spinorbit coupling in a free ion behaves, within pertubation. In this way, it differs from direct exchange in which there is coupling between nearest neighbor cations not involving an intermediary anion. Cayleytree ising model with antiferromagnetic nearestneighbor and ferromagnetic equivalentneighbor interactions.
Antiferromagnetic interlayer coupling in ferromagnetic. Although bulk zinc ferrite is an antiferromagnetic material having a neel temperature around 10 k, it has been reported to have a magnetization value of 11 emu g. Antiferromagnetic coupling in cdseznmnse quantum dot structures daniel dagnelund, q. Control and detection of spin order in ferromagnetic materials is the main principle enabling magnetic information to be stored and read in. A robust soliton ratchet using combined antiferromagnetic. Determination of antiferromagnetic coupling constants in. Antiferromagnetic coupling of tbpc2 molecules to ultrathin.
In a simple system pay attention to that word, a ferromagnetic coupling implies that j 0. Us20060263643a1 laminated magnetic thin films with weak. Pdf we have worked out the ferromagnetic resonance fmr mode. The behaviors of the coercivity are nonmonotonic due to the energy competitions and the thermal fluctuations. But close to zero field the superposition of a second contribution becomes visible. Antiferromagnetic coupling in cdseznmnse quantum dot. In 1949 it was shown that the antiferromagnetic structure could be revealed and studied by the methods of neutron diffraction.
We show that by coupling the valley degree of freedom to antiferromagnetic order, there is an emergent electronic degree of freedom characterized by the product of spin and valley indices, which leads to spinvalleydependent optical selection rule and. It is noteworthy that two magnetic structures separated by nm gap exhibit ferromagnetic or antiferromagnetic couplings 10. Moore1,2 1department of physics, university of california, berkeley, california 94720, usa 2materials sciences division, lawrence berkeley national laboratory, berkeley, california 94720, usa received april 2010. Antiferromagnetic coupling across silicon regulated by. Max metlitski harvard erez berg matthias punk saturday, october 20, 12. Describing antiferromagnetism in density functional theory dft had been an unsolved problem since the 1930s until recently. Here the realization of antiferromagnetic coupling in coreshell nanoparticles adds a new possibility to tune.
From antiferromagnetic to ferromagnetic coupling for v. Antiferromagnetic coupling is an effect that is often important for molecules with high spin multiplicity like this bridged manganese complex. Antiferromagnetic coupling and perpendicular anisotropy in. The robust antiferromagnetic coupling is stabilized by a superexchange interaction, driven by the outofplane molecular orbitals responsible of the magnetic ground state and electronically decoupled from the underlying metal via the graphene layer, as confirmed by ab initio theoretical predictions. These data suggest that the exchange constant for freestanding fe chains is.
Apr 21, 2010 magnetic properties of antiferromagnetic oxide materials. Pdf study of antiferromagnetic coupling by ferromagnetic. The antiferromagnetic exchange coupling at the interface leads to antiparallel orientation of the magnetizations of thin adjacent sro and lsmo layers which can be sustained in a magnetic. Antiferromagnetic domain wall motion driven by spinorbit. Superexchange, or kramersanderson superexchange, is the strong usually antiferromagnetic coupling between two nexttonearest neighbour cations through a nonmagnetic anion.
Signproblem free quantum monte carlo for the onset of antiferromagnetism. Antiferromagnetism an overview sciencedirect topics. In materials that exhibit antiferromagnetism, the magnetic moments of atoms or molecules, usually related to the spins of electrons, align in a regular pattern with neighboring spins on different sublattices pointing in opposite directions. When multiple pairs of layers are used, they are separated by layers of nonmagnetic material. Kimichika fukushima, in advances in quantum chemistry, 2015. Origin of the antiferromagnetic coupling between endohedral gd and the free spin on the carbon cage.
Cookies enable us to provide the best experience possible and help us understand how visitors use our website. Correlation between antiferromagnetic interface coupling. Antiferromagnetic coupling of tbpc 2 molecules to ultrathin ni and co films. The supporting information is available free of charge on the acs. Antiferromagneticferromagnetic coupling physics forums. Theory of ferromagneticantiferromagnetic interface coupling. This is a typical transition metal system in which antiferromagnetic coupling is of interest. Us4103315a antiferromagneticferromagnetic exchange bias. Antiferromagnetic coupling and perpendicular anisotropy in tbfeconio multilayers r.
Hill b a science division, truman state university, kirksville, mo 63501 b department of physics, university of florida, gainesville, fl 32611 abstract electron spin resonance was used to study the spindimer compound. In these systems, a quantum critical point emerges as external parameters such as chemical doping are varied. Electricfieldinduced antiferromagnetic resonance in. Tuning the magnetic coupling across ultrathin antiferromagnetic. By browsing materials today, you agree to our use of cookies. Control and detection of spin order in ferromagnetic materials is the main principle enabling magnetic information to be stored and read in current technologies. This spontaneous antiparallel coupling of atomic magnets is disrupted by heating and disappears entirely above a certain temperature, called the neel temperature, characteristic of each antiferromagnetic material.
Antiferromagnetic coupling in semiconductors materials today. Interlayer couplings mediated by antiferromagnetic magnons. These archetypal spin interfaces can be prototypes to demonstrate how antiferromagnetic andor ferromagnetic coupling can be. The free energy per unit area of the magnetically coupled bilayer system is.
A robust soliton ratchet using combined antiferromagnetic and ferromagnetic interlayer couplings r. Enhancement of ferromagnetic coupling in mngaas digital ferromagnetic heterostructure by freehole injection m. For submonolayer coverage the coupling between v and co is clearly of antiferromagnetic type whereas it changes to ferromagnetic coupling in the case of a full v monolayer on co001. Interlayer couplings mediated by antiferromagnetic magnons ran cheng,1,2 di xiao,1 and jiangang zhu2,1 1department of physics, carnegie mellon university, pittsburgh, pa 152 2department of electrical and computer engineering, carnegie mellon university, pittsburgh, pa 152 collinear antiferromagnets afs support two degenerate magnon excitations carrying opposite. Pdf ferromagnetic and antiferromagnetic coupling of spin. The neel temperature is named for louis neel, french physicist, who in 1936 gave one of the first explanations of antiferromagnetism. In a simple system pay attention to that word, a ferromagnetic coupling implies that j antiferromagnetic coupling means that j 0. Coupling the valley degree of freedom to antiferromagnetic. Conventional electronics are based invariably on the intrinsic degrees of freedom of an electron, namely, its charge and spin. Because of the strong coupling nature of this critical point and the sign problem plaguing numerical quantum monte carlo qmc. Antiferromagnetic material an overview sciencedirect. B when citing this work, cite the original article. Antiferromagnetic interfacial coupling and giant magnetic hysteresis in la0. Lcmo has an inplane tensile strain and is almost strain free in sls grown on the sto substrate, from our analysis of the lattice parameters.
The shape is dominated by a paramagnetic signal that one would expect for a free molecule at a temperature of t. The robust antiferromagnetic coupling is stabilized by a. Antiferromagnetism magnetic moments of atoms align antiparallel to produce a. Strong coupling of microwave photons to antiferromagnetic. Large exchange coupling field in perpendicular synthetic. Read antiferromagnetic coupling in semiconductors on materials today the gateway for electronic properties news. T1 correlation between antiferromagnetic interface coupling and positive exchange bias. Mar 05, 20 we show that by coupling the valley degree of freedom to antiferromagnetic order, there is an emergent electronic degree of freedom characterized by the product of spin and valley indices, which leads to spinvalleydependent optical selection rule and berry curvatureinduced topological quantum transport. With the decrease of temperature, three distinct behaviors of the eb are obtained as a result of the state transitions of the afm spins from completely free via partially free and partially frozen, and, finally, to completely frozen. Antiferromagnetic coupling between ferromagnetic layers has been observed for the first time in allsemiconductor superlattice structure euspbs001, by. Ferromagnetic and antiferromagnetic coupling of spin. The interplay of antiferromagnetism and superconductivity. The quantum theory of antiferromagnetism in metals is necessary for our understanding of numerous intermetallic compounds of widespread interest. Magnetic nanoparticles are studied for their potential use in nanomagnetic devices.
72 238 1198 1384 755 389 1097 187 684 548 110 549 660 799 271 1028 671 263 575 1252 10 498 101 1067 503 77 47 376 1386 371 438 1243 1181 730 96 755 108 594 1490 846