We have included in the definition of these states the free evolution phase factor. This thesis is brought to you for free and open access by the graduate school at lsu digital commons. Parker department of pure and applied physics, university of salford, salford m5 4wt, uk invited paper a discussion is given of the historical background of the kerr magneto optic effect as well as of details of the original experiments leading to its discovery. Spinorbit torque magnetometry by widefield magneto. Highresolution magneto optic kerr effect for spintronics applications. View magneto optic kerr effect ppts online, safely and virus free. Here we present a widefield moke technique that adopts a kohler illumination. Magneto optic kerr effect moke microscopy2 provides the most accessible platform to study the dynamics of spins, magnetic quasiparticles, and domain walls3,4,5,6. In physics the magnetooptic kerr effect moke or the surface magnetooptic kerr effect. Magneto optical kerr effect moke is an efficient approach to probe surface magnetization in thin film samples. Development of a surface magnetooptic kerr effect magnetometer susan stoffer sorensen department of physics and astronomy bachelor of science this thesis presents the development and optimization of a surface magnetooptic kerr effect smoke magnetometer. Control light with heat and magnets magneto optical kerr effect. While the kerr effect has been used extensively for the study of magnetic materials, it is only.
These are perpendicular and parallel to the optical plane of the incident light on the sample s. Winner of the standing ovation award for best powerpoint templates from presentations magazine. Magnetooptic effect synonyms, magnetooptic effect pronunciation, magnetooptic effect translation, english dictionary definition of magnetooptic effect. Free software computes the magnetooptic kerr effect of multilayered thin films. Magneto optic effect synonyms, magneto optic effect pronunciation, magneto optic effect translation, english dictionary definition of magneto optic effect. Keywords magneto optic effect, faraday effect, kerr effect, polarization, magneto electronics 1. Magnetic and spintronic media have offered fundamental scientific subjects and technological applications. Formulas are established which account for the performance of the type of equipment necessary for the measurement or application of the kerr magneto optic effect in ferromagnetic films.
Introduction the interaction of light with matter is affected by the. Magneto optic kerr effect moke 18 elements, o and c, with respect to the s and p directions. The source of this optical anisotropy is the magnetisation m within surface domains which can be influenced by external forces such as magnetic fields. Pdf extended longitudinal vector and bragg magnetooptic. Cotton mouton effect birefringence effect signal proportional to m.
However, in the research of nanoscale spin textures and stateofthe. Pdf magnetooptical detection of the spin hall effect in. Magnetooptic effect article about magnetooptic effect by. Some practical applications of the faraday magnetooptic. The magneto optical kerr effect moke has proved to be a useful research tool for understanding ferromagnetism and magnetic hysteresis. This is due to its sensitivity, local probing nature, and experimental simplicity. Introduction birefringence firstdescribedbyrasmus bartholinin1669.
Extended longitudinal vector and bragg magneto optic kerr effect for the determination of the chirality distribution in magnetic vortices. This has the effect that the optical rotation of the plane of polarization is only observed for rays travelling quite close to the optic axis. Pdf gatecontrollable magnetooptic kerr effect in layered. The development of an ac magneto optic kerr effect system for the. Magnetooptical effect definition of magnetooptical effect. They also coined the term surface magnetooptic kerr effect. Magneto optical kerr effect microscopy in our capstone project we built a magnetooptical kerr effect microscope which will be used in development and characterization of magnetic materials and devices in the center of microwave magnetic materials and integrated circuits at northeastern university. The magneto optical kerr effect moke has been intensively studied in a variety of ferro and ferrimagnetic materials as a powerful probe for electronic and magnetic properties 1,2,3 and for. A novel sensor technique using a magnetic thin film as the sensing element and the magneto optic kerr effect as the optical read technique has been tested experimentally through magnetic field measurements. Furthermore, a theory is developed to describe the modification of the kerr effect by dielectric layers deposited on the ferromagnetic surfaces. Electricmagnetooptical kerr effect in a hybrid organic. These results show that optical interference effect can be utilized to study the magnetooptical properties of ultrathin films. Magneto optic kerr effect moke microscopy provides the most accessible platform to study the dynamics of spins, magnetic quasiparticles, and domain walls. Magneto optical kerr e ect moke magneto optical kerr e ect moke jaroslav hamrle jaroslav.
Theelectro optical,opticalandmagnetoopticalkerreffect. Interference induced enhancement of magnetooptical kerr effect in. The fundamental observation is that isotropic materials, e. The kerr effect, named after its discoverer 1875, is an electrooptical feature involving. The source of this optical anisotropy is the magnetisation m within surface domains which can be influenced by external forces such as magnetic. Versatile magnetooptic kerr effect polarimeter for studies of domainwall dynamics in magnetic nanostructures corneliu nistor, geoffrey s. The kerr magnetooptic effect 18761976 sciencedirect. Magneto optic effects faraday, cottonmouton the polarization, and consequently, the permittivity can depend on the. Yig, which is relevant for magneto optic readout applications that are based on reflection geometry. What is the longitudinal magnetooptical kerr effect. Magnetooptic kerr effect moke as well as lightscattering ls from spinwaves have now emerged as powerfull tools to measure some properties of thin. Bulk mn 3 sn crystals were used for the moke spectroscopy measurement.
Magnetooptical kerr effect how is magnetooptical kerr. That branch of physics which deals with the influence of a magnetic field on optical phenomena. In physics the magnetooptic kerr effect moke or the surface magnetooptic kerr effect smoke is one of the magneto optic effects. Mansel davies, in some electrical and optical aspects of molecular behaviour, 1965. The kerr electro optic effect, or dc kerr effect, is the special case in which a slowly varying external electric field is applied by, for instance, a voltage on electrodes across the sample material. There are important differences in the moke depending on the direction of magnetization with respect to the direction of polarization. Moke microscope magnetooptical kerr effect microscope pdf.
Firstorder reversal curves forc are a powerful method for magnetic sample characterization, separating all magnetic states of an investigated system according to their coercivity and internal magnetic interactions. Magneto optical effect synonyms, magneto optical effect pronunciation, magneto optical effect translation, english dictionary definition of magneto optical effect. Application of magnetooptical kerr effect to firstorder. The kerr effect is distinct from the pockels effect in that the induced index change is directly proportional to the square of the electric field instead of varying linearly with it. Under this influence, the sample becomes birefringent, with different indices of refraction for light polarized parallel to or perpendicular to the applied field. Magnetooptic kerr effect of strongly correlated electron. This system should then probe a purely magnetic faraday rotation, namely the gyromagnetic faraday effect 19, 21. Magnetooptic kerr effect sensors for fiber optic applications. These two monumental works heralded the beginnings of magneto. Magneto optical detection of the spin hall effect in pt and w thin films.
The moke occurs when light reflected from the surface of a. Magneto optical effects in magnetic materials arise due to the optical anisotropy of the materials. Magnetooptic kerr effect ccd imaging with polarization. Pdf theory of the magnetooptical kerr effect in ferromagnetic.
Jan 26, 2018 the magneto optical kerr effect moke has been intensively studied in a variety of ferro and ferrimagnetic materials as a powerful probe for electronic and magnetic properties 1,2,3 and for. Development of a surface magneto optic kerr effect magnetometer susan stoffer sorensen department of physics and astronomy bachelor of science this thesis presents the development and optimization of a surface magneto optic kerr effect smoke magnetometer. It is used in materials science research in devices such as the kerr microscope, to investigate the magnetization structure of materials. Magneto optic kerr effect research papers academia. The results of reflection from a magneto optic material are known as the magneto optic kerr effect not to be confused with the nonlinear kerr effect. It is desired to adapt the surface magneto optic kerr effect setup to an existing vacuum system already containing a vaporizer, mass spectrometers, leed, and a stm. The kerr effect, named after its discoverer 1875, is an electrooptical feature involving the orientation of the molecules by the action of an electric field and the anisotropy of the polarizability then observable in the medium. The surface magneto optic kerr effect smoke has significantly impacted research on magnetic thin films. However, in the research of nanoscale spin textures and stateoftheart spintronic devices, optical techniques are generally. Relevant theoretical characteristics of these effects and its application in modern technology are also discussed. Magnetic field dependence of the magneto optical kerr effect moke shown in figs. Some practical applications of the faraday magnetooptic effect, the kerr electrooptic effect, and the pockels electrooptic effect in the early decades of the 20th century. Spinorbit torque magnetometry by widefield magnetooptical. Control light with heat and magnets magnetooptical kerr.
Osa magnetooptic polar kerr and faraday effects in. Experimentally it will be shown that the magnetooptic kerr effect moke. Highresolution magnetooptic kerr effect for spintronics. In a magneto optic material the situation is a bit different. The magnetic hysteresis curves measured by moke change the shape depending on the photon energy and therefore deviate from those measured by superconducting quantum interference device squid. Over the last decades, the magneto optical kerr effect moke has gained widespread popularity as a characterization tool for the study of magnetism and magnetic materials 1, 2. Magnetooptic effect definition of magnetooptic effect. A lowtemperature kerr effect microscope for the simultaneous magneto optic and magneto transport study of magnetic topological insulators to cite this article. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. Finally the concept of magneto optic kerr effect is discussed and a setup utilizing the effect for magnetic probing is presented. For the kerr effect the magnetooptical interaction between light and. The research activities on the phenomenon of magneto optic effects has recently promulgated due to its versatile use in magneto optic recordings for high density magnetic data storage, magnetic field sensors and its applications in magneto electronics. Magnetic field dependence of the magneto optical kerr effect moke was measured by using a commercial system nanomoke3, quantum design.
As the moke in yig is known to be small for wavelengths in the red and nearinfrared spectral range, used for optical communications. Relying on small, magnetization induced changes in the optical properties which in turn modify the polarization or the intensity of the re. Control light with heat and magnets magnetooptical kerr effect. In this presentation the principles of magnetooptical microscopy, mostly kerr microscopy and mag. The method is based on the magneto optical faraday or kerr effect, i. The resulting formulas satisfactorily describe the appropriate. Theory of the magnetooptical kerr effect in ferromagnetic compounds. This magnetically induced change of polarization is called the magneto optic kerr effect moke, as opposed to the electro optic kerr effect which kerr discovered later. This effect is usually found in colloidal solutions of magnetic particles and as m might be large 0cm is too.
In general, magneto optic effects break time reversal symmetry locally i. The optic axis of this induced optical activity is aligned with the axis of the applied magnetic field. Development of a surface magnetooptic kerr effect magnetometer. Magnetooptical kerr e ect moke photonphoton spectroscopies absorption ii. Perfect optical absorptionenhanced magnetooptic kerr. Pdf the development of an ac magneto optic kerr effect system. The kerr effect, also called the quadratic electro optic qeo effect, is a change in the refractive index of a material in response to an applied electric field. Erskine department of physics, the university of texas at austin, austin, texas 78712 received 22 june 2006.
A major drawback of using measurement techniques like vsm or squid, typically applied for forc acquisition, is the long measurement time, limiting the resolution and the number. Magneto optical kerr effect longitudinal, polar, timeresolved transient moke background the magneto optical kerr effect moke and the faraday effect describe the change in polarization of incident light as it is reflected or transmitted by a magnetic material. Measurement of magneto optic kerr effect using piezobirefringent modulator j. Reflection mode the second category of magneto optic effects deals with reflected light from the surface of a magnetized material. Excites vicinity of the fermi surface all dc conductivities, va characteristics. Pdf the experimental and theoretical aspects of obtaining the magnetic information carried by laser beams diffracted from an array of nanosized. The faraday and kerr effects abstract though discovered over a century ago, the faraday and kerr effects of polarized light are two of the most instrumental components of optical communication technology today. Parker department of pure and applied physics, university of salford, salford m5 4wt, uk invited paper a discussion is given of the historical background of the kerr magnetooptic effect as well as of details of. Measurement of the resonant magnetooptical kerr effect.
The magneto optic kerr effect moke is the study of the re. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. We have developed a magneto optic kerr effect moke imaging system with a chargecoupleddevice ccd camera by using the rotating compensator technique. Leo kristjansson, april 2017 research on very rapid processes let a beam of ordinary light pass through a polarizing nicol prism and a glass vessel. Magnetism, light and the magneto optic kerr effect youtube. Considering the fact that light is electromagnetic. Magnetooptical effect article about magnetooptical effect. The magnetooptical kerr effect moke has been intensively studied in a variety of ferro and ferrimagnetic materials as a powerful probe for. Moreover, the kerr angle can be switched by reversal of both ferroelectric and magnetic. It describes the changes to light reflected from a magnetized surface.
The polar and longitudinal kerr effects are characterized by a complex rotation of the plane of polarization of linearly polarized incident light upon reflection from the surface of a ferromagnetic material. Control light with heat and magnets magneto optical kerr effect applied science. Semantic scholar extracted view of the development of an ac magneto optic kerr effect system for the characterization of pulsed laser. Large magnetooptical kerr effect and imaging of magnetic octupole. The discovery of magneto optical effects evoked a new thought that the nature of light was an electromagnetic entity, and played a central role. Macroscopically, this effect can be described by the presence of antisymmetric, offdiagonal measurement science and technology a lowtemperature kerr effect microscope for the simultaneous magneto optic and magneto transport study of magnetic topological insulators. Quadratic electro optic effect kerr effect s l s ij ijklek e. The branch of physics that deals with phenomena associated with magnetic effects on matter as. Polar magneto optical kerr effect moke spectroscopy in the energy range from 1. The kerr effect, named after its discoverer 1875, is an electro optical feature involving the orientation of the molecules by the action of an electric field and the anisotropy of the polarizability then observable in the medium.
Di erent energy ranges probes di erent part of the electronic structure of the matter. The chapters discuss negative refraction, negative refractive index and subwavelength imaging, magneto optics and the kerr effect with ferromagnetic materials, symmetry properties of nonlinear magneto optical effects, optical magnetism in plasmonic metamaterials, chiral photonic media, optical vortices, photonic crystals, wave interference and modes in random media, chaotic behaviors of random. Control light with heat and magnets magnetooptical kerr effect applied science. View magneto optic kerr effect research papers on academia. Moke proved to be especially well suited to investigate magnetization effects at the nanoscale where it was first utilized in 1985 by moog and bader to measure magnetic hysteresis loops of fe monolayer films. Magnetic and spintronic media have offered fundamental scientific subjects and technological applications1. Magnetooptic mo effects in magnetic multilayers with periodically stratified regions are analyzed for the case of normal light wave incidence and polar magnetization faraday and polar kerr effects. The branch of physics that deals with phenomena associated with magnetic effects on matter as it emits light, having applications in computer. Magnetooptic kerr effect and lightscattering from spinwaves. Perfect optical absorptionenhanced magnetooptic kerr effect. Recent citations controlling the transverse magneto. Electroopticalkerreffect opticalkerreffect magneto opticalkerreffect 5. Large magnetooptical kerr effect and imaging of magnetic.
Fielddependent magnetooptical kerr effect spectroscopy. Here using firstprinciples computations, we show that, in a perovskite metalorganic framework mof, the magnetic and electric orders are further coupled to optical excitations, leading to an electric tuning of the magneto optical kerr effect emoke. The polar magneto optic kerr effect system characterizes the magnetic properties of the perpendicular magnetic recording pmr layer immediately after deposition, an important factor in the yield of disk drive media. Enhanced magnetooptic kerr effect and magnetic properties. To isolate the magneto optic kerr effect of the sample, we use the following procedure, which is illustrated in fig. Sensitivity results obtained using a simple free space ellipsometry measurement system show a magnetic. The magnetooptic kerr effect moke technique is well established for the investigation of magnetic materials. Here we present a widefield moke technique that adopts a. A lowtemperature kerr effect microscope for the simultaneous. Drude term description of absorption due to free electrons.
It is the equivalent of the kerr electro optic effect. The magnetooptical kerr effect moke has proved to be a useful research tool for understanding ferromagnetism and magnetic hysteresis. Versatile magnetooptic kerr effect polarimeter for. The nature of these properties is the manner in which the polarization of light is affected by an electromagnetic. Description of optical properties of materials iii. Magnetooptical kerr effect moke is an efficient approach to probe surface magnetization in thin film samples. Magneto optic kerr effect the kerr effect was discovered in 1877 22 it appears when a linearly polarised electromagnetic wave is reflected on a metal surface in presence of an electric or magnetic field moke. To ease the design of the system, a preliminary simpled surface magneto optic kerr setup is fabricated outside of vacuum.
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