共查询到20条相似文献,搜索用时 31 毫秒
1.
在北京同步辐射装置(BSRF)的3W1B软X射线光束线上利用自行研制的同步辐射软X射线综合偏振测量装置对Ni的M2,3边附近(60—70 eV)进行了软X射线磁光(magneto-optical)法拉第效应(Faraday effect)的偏转测量,实验装置主要由起偏器,检偏器,样品架,圆形钕铁硼永磁铁和MCP探测器组成,偏振元件(起偏元件和检偏元件)均采用反射式非周期性Mo/Si宽带多层膜.实验采用反射起偏和反射检偏的模式,得到一系列能量范围在60—70 eV间的法拉第偏转角结果,
关键词:
软X射线
磁光Faraday效应
综合偏振测量装置
宽带多层膜 相似文献
2.
V. G. Kravets A. K. Petford-Long A. F. Kravetz 《Physica E: Low-dimensional Systems and Nanostructures》1999,4(4):292
Granular films of composition (CoFe)x(HfO2)1−x with continuous variation of the Co0.5Fe0.5 volume fraction in the range 0.1<x<0.9 have been prepared by e-beam co-evaporation. The optical properties of the thin granular composite films have been determined from transmission and reflection spectra in the 300–1100 nm region. The optical characteristics of the granular films as a function of x were also determined by the ellipsometrical method at λ=632.8 nm. We find that the transmission and reflection spectra and the dielectrical function have anomalies near the percolation threshold at xp≈0.45. The Faraday rotation in the films was determined at λ=632.8 nm. The spectral dispersion of Faraday effects have peak in the region of the plasmon frequency. The Faraday effect is greatly enhanced near xp. The calculated optical and magneto-optical parameters, described in the framework of the effective medium approximation, are in qualitative agreement with experimental data. 相似文献
3.
The transmission light intensity method is carried out on a classical platform to study the reciprocity of Faraday effect in water-based Fe3O4 ferrofluid and its diluents. Setting the polarization direction of the analyzer at an angle of 45° to that of the polarizer, the switchable DC magnetic field and the alternating magnetic field are imposed to ferrofluid. The ferrofluid film is replaced by magneto-optical glass for contrastive experiments. The results indicate that ferrofluid is different with magneto-optical glass. Even though the direction of magnetic field is reversed, the rotation direction of the polarized light does not change for ferrofluid. The theoretical model of magneto-optical rotation was used to describe the origin of the reciprocity of Faraday effect in ferrofluid and the non-reciprocity in magneto-optical glass. These findings suggest that the magnetic moments of nanoparticles in ferrofluid tend to the same orientation with the magnetic field because of the rotation of particles. 相似文献
4.
《Journal of magnetism and magnetic materials》1999,192(2):233-237
Magnetic and magneto-optical properties of MnSb films with different crystalline orientations on various semiconductors of GaAs(1 0 0), GaAs(1 1 1)A, B, and sapphire(0 0 0 1) have been measured by a vibrating sample magnetometer (VSM) and a home-made magneto-optical Kerr effect (MOKE) system. All these samples have their easy axes in the plane and show ferromagnetic properties. Among these samples, the film on GaAs(1 1 1)B has the lowest coercive force Hc and the largest squareness (SQ) value, whereas the film on GaAs(1 0 0) shows the largest Hc and the lowest SQ value. A large Kerr rotation angle of about 0.3° was observed at a wavelength of λ=632.8 nm for the film on sapphire in the field applied both parallel and perpendicular to the film plane. However, the MnSn films on other substrates do not have an observable Kerr rotation. The dynamic effect of the hysteresis was also measured using our MOKE system. As the frequency of applied magnetic field increases, the loop rounds off at the corners and the loop area increases. 相似文献
5.
F. Vidal P. Schio N. Keller Y. Zheng D. Demaille F.J. Bonilla J. Milano A.J.A. de Oliveira 《Physica B: Condensed Matter》2012,407(16):3070-3073
Sequential pulsed laser deposition of CoO and CeO2 at 650 °C under vacuum leads to the formation of a slanted Co nanowires assembly embedded in CeO2/SrTiO3(0 0 1) epilayers. High temperature magneto-optical Faraday measurements were performed, which revealed a Faraday ellipticity of 1.3° at a wavelength of 450 nm for 300 nm thick samples and which allowed to access the magnetic properties. From the analysis of the coercivity dependence on temperature, it is shown that the magnetic anisotropy of the slanted Co nanowires is dominated by shape anisotropy and that their magnetization reversal is localized. 相似文献
6.
Quantum theory of the magneto-optical effect and magnetization of Nd-substituted yttrium iron garnet
F. Zhang Y. Xu J.H. Yang M. Guillot 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(2):165-175
The magneto-optical and magnetic properties of Nd 3+ ions in Y 3Fe 5O 12 garnet are analyzed by using quantum theory. In the spontaneous state, the magneto-optical effects originate mainly from
the intra-ionic electric dipole transitions between the 4 f
3 and 4 f
25d states split by the spin-orbit, crystal field, and superexchange interactions. For the excited configuration, the coupling
scheme of Yanase is extended to the Nd 3+ ion. The magneto-optical resonance frequencies are mainly determined by the splitting of the 5d states induced by the crystal field. The theoretical results of both Nd magnetization and Faraday rotation are in good agreement
with experiments. The observed Faraday rotation is proved to be of the paramagnetic type. Although the value of the magneto-optical
resonance frequency derived from a macroscopic analysis is approximately confirmed by our theoretical study, a new assignment
about the transitions associated with this resonance is unambiguously determined. The spin-orbit coupling of the ground configuration
has a great influence on both the Faraday rotation and magnetization, but, unlike the theoretical results obtained in some
metals and alloys, the relation between the Faraday rotation and the spin-orbit coupling strength is more complex than a linear
one. The magnitude of the magneto-optical coefficient increases as the spin-orbit interaction strength of the ground configuration
decreases when the strength is not very weak. Finally, the temperature dependence of the magneto-optical coefficient and the
effect of the mixing of different ground-term multiplets induced by the crystal field are analyzed.
Received 8 November 2000 相似文献
7.
The giant magneto-optical Faraday effect (giant Faraday rotation) of ferromagnetic metal–semiconductor matrix Fe–ZnSe granular films prepared by radio frequency sputtering is studied. The result shows that the Faraday rotation angle θF value of the granular films sample with Fe volume fraction x=35% is of the order of 105 °/cm at room temperature. Temperature dependence of the θF of Fe0.35(ZnSe)0.65 granular films shows that θF value, below 150 K, increases rapidly with the decrease of the temperature, and when T=10 K θF value is 6×105 °/cm. Through the study of the structure and dependence of magnetic properties on temperature, it has been found that the remarkable increase of the θF value of Fe0.35(ZnSe)0.65 granular films below 150 K seems to arise from the sp–d exchange interaction inside the granular films. 相似文献
8.
A theory of the polar magneto-optical Kerr effect in a layer of small ferromagnetic particles has been developed in the framework
of the Green’s function method of electrodynamics. The manifestation in magneto-optics of the local field effect, which is
initiated by the contribution to the effective field of dipole moments induced in particles, has been studied in terms of
the model of a square lattice of ferromagnetic ellipsoids. The magneto-optical Kerr effect stimulated under normal incidence
of a linearly polarized electromagnetic wave on a layer of particles magnetized perpendicular to the layer plane has been
analyzed. The dependence of the Kerr rotation angle in an array of ellipsoidal Co particles embedded in the transparent dielectric
CaF2 on the light frequency, the parameters of the ellipsoidal particles, and the lattice period (concentration of the magnet
in the layer) has been studied numerically. It has been shown that, within a broad (2.0–4.5 eV) spectral range, the local
field effect studied as a function of increasing concentration of Co particles in the layer manifests itself in the reversal
of the sign of the Kerr rotation compared to that observed in a single ellipsoid or a solid Co film. 相似文献
9.
V.V. Pavlov P.A. Usachev D.A. Kurdyukov A.V. Kimel Th. Rasing 《Journal of magnetism and magnetic materials》2009,321(7):840-842
Optical and magneto-optical properties of three-dimensional magnetic photonic crystals, based on magnetite Fe3O4 embedded into an opal film matrix, are investigated in both transmission and reflection. A strong enhancement of the polar Kerr effect and a modification of the Faraday effect have been found near the photonic band-gap of about 1.8 eV. Unusual changes of hysteresis curves and their dependence on photon energy have been revealed in the spectral region where the magneto-optical effect reverses its sign. This phenomenon has been explained by two types of magnetite particles inside the opal matrix having different coercive fields and spectral behaviour. 相似文献
10.
Hanju Lee Songhui Kim Seungwhan Kim Takayuki Ishibashi Kiejin Lee 《Journal of magnetism and magnetic materials》2010,322(18):2722-2727
We observed the magnetic domains of a magnetic card by using the bismuth-substituted yttrium iron garnet (Bi-YIG; Bi1Y2Fe5O12) thin films as the indicator films. The magnetic domains’ dependence on the preparation conditions of the garnet thin film crystals was visualized by using a magneto-optical microscope. Garnet thin films were fabricated on glass substrates using a metal-organic decomposition method (MOD). We found that bigger Faraday rotation was measured in the better crystallized indicator films. Polycrystalline Bi-YIG thin films were successfully obtained for the annealing temperature of 700 °C and an annealing time of 1 h. The thickness of the film was about 47 nm for a single coating during the MOD process. The Faraday-rotation angle of the films was estimated as −2.47°/μm and the angle was comparable to other synthesis methods, such as the sol-gel and the RF-magnetron sputtering. Using these indicator films, we could image the magnetic domains of magnetic materials. 相似文献
11.
New semiconductor compound Cd1?xMnxTe exhibits strong Faraday rotation in the interband region. It is shown by measurements of magneto-optical Kerr effect and reflection in magnetic field that unusually large exciton Zeeman splitting plays an essential role in the observed Faraday rotation. A possible explanation of the observed splitting (corresponding to a “g factor” value up to 100) by exchange interaction of excitons with manganese d states is suggested. 相似文献
12.
The magneto-optical susceptibility and magnetic hysteresis loops of the Faraday effect, which accompany the technical magnetization of the iron garnet Tb3Fe5O12, have been investigated experimentally in the temperature region near the magnetic compensation point of this ferrimagnet T c = 249 K. It has been found that, during the technical magnetization as the temperature approaches the magnetic compensation point T c , the velocity of domain walls increases, whereas the magneto-optical susceptibility has local maxima to the right and to the left from T c . Mentioned features of magneto-optical properties of the iron garnet Tb3Fe5O12 are associated with the resonance natural frequency of the domain wall oscillations in the crystal with the frequency of the alternating magnetic field. It has been shown that the used theoretical model of the magnetic resonance of domain walls makes it possible to consistently describe (at the qualitative level) the revealed regularities of the variation of the Faraday effect in the iron garnet Tb3Fe5O12 near T c . 相似文献
13.
The structure and magneto-optical properties of fine-grain garnet thin films crystallized by the rapid recurrent thermal annealing (RRTA) method have been studied. The RRAT method has been used to crystallize BiGaDyIG garnet single-layer or BiGaDyIG/AI double-layer films and to get nanometer grain size (about 30–50 nm), which results in a large Faraday rotation angle, a smoother surface and fewer voids in the films. Meanwhile we have discovered that the Faraday rotation angle increases with the number of recurrences during the rapid annealing and quenching. With the more recurrent annealing one can not only get a strong Faraday effect, but it suppresses the appearance of DyFeO3 phase in garnet films, which has been explained very well. By applying the new method, the as-deposited films have been succesfully crystallized to the (BiDy)3(FeGa)5O12 garnet phase. They exhibited excellent magneto-optical properties with a coercivity of about 1500 Oe and effective Faraday rotation angle of 1.5°. The composition, magnetic and magneto-optical properties of the crystallized garnet films have been examined. 相似文献
14.
论述了在交变磁场下测量磁光薄膜动态法拉第效应的原理和方法,利用此方法,在不同的调制磁场强度和频率下测量磁光薄膜的动态法拉第旋转特性,获得了较好的测量结果,并对测量误差进行了分析。 相似文献
15.
X. Zhang Y. Xu M. Guillot 《The European Physical Journal B - Condensed Matter and Complex Systems》1999,9(2):187-199
To reveal the physical origin of the giant magneto-optical enhancement of Ni2+ ions in barium ferrite, quantitative calculations of the contributions of both the intra-ionic electric dipole transition
between the 3d8 and 3d7 4p configurations of the Ni2+ ions and the intra-ionic electric dipole transition induced by odd-parity crystal field terms are presented. It is deduced that the transition is important in the origin of the considered magneto-optical enhancement. The most important factor is the Ni-Fe
superexchange interaction; since it is strong enough, the Faraday rotation produced by the Ni2+ ions is large though the energy difference between the 3d8 and 3
d7
4
p configurations is large. It is demonstrated that though the intra-ionic electric dipole transition does produce Faraday rotation peaks in the visible range, their magnitude is too small to explain the observed
Faraday rotation. The effect of the spin-orbit interaction on the Faraday rotation is analysed. The spin-orbit interaction
of the ground configuration plays a very important role in the occurrence of Faraday effects, but the Faraday rotation does
not increase linearly with the strength of the spin-orbit coupling. On the contrary, the spin-orbit interaction of the excited
configuration has almost no effect on the Faraday rotation. It is shown that the mixing of the different multiplets of the
ground term induced by the crystal field has a great influence on the magneto-optical properties.
Received 7 January 1998 相似文献
16.
Yu A. Barnakov 《Journal of Physics and Chemistry of Solids》2004,65(5):1005-1010
We report the size-dependent magneto-optical properties of nanometer-sized magnetite particles embedded in poly(methyl methacrylate). The nanocomposite material contains Fe3O4 particles with diameters ranging from 8 to 200 nm. Faraday rotation spectra are measured in the wavelength range of 400-900 nm. A broad spectral band centered at 650 nm (1.91 eV) is observed in the for the larger (200 nm) particles. Decreasing of nanoparticle size leads to a significant narrowing of this band and appearance of an additional peak in the 2.5-3.2 eV range. We propose that the changes to the spectrum are caused by structural changes in the small particles, which affect the magneto-optically active charge transfer and orbital promotion electronic transitions. In addition, the Faraday rotation spectrum of the composite containing 8 nm particles is sensitive to nanoparticle concentration. Increasing the concentration of nanoparticles in the composite results in a red shift of the spectral feature at approximately 450 nm. We propose that the shift of the peak in Faraday rotation spectrum is due to particle-particle interactions in the concentrated sample. Ferromagnetic Resonance measurements confirm a magneto-static interaction in the concentrated sample not present in the diluted sample. 相似文献
17.
Influence of Ni content on the microstructure and magnetic and
magneto-optical (MO) properties of sputtered (Co1-xNix)Pt3
alloy films has been investigated by means of Kerr spectrometer, Kerr
hysteresis looper, X-ray diffractometer (XRD), and atomic force microscopy
(AFM). On the whole, the addition of Ni to the CoPt3 alloy film
simultaneously decreases the Curie temperature TC and the Kerr rotation
angle θK, but the decrease of TC with Ni content is more
visible. When the Ni content x is increased from 0 to 0.33, TC
decreases from 273 ○C to 233 ○C, whereas the decrease of
θK is quite limited and the film still preserves a strong
perpendicular magnetic anisotropy (PMA) and a high coercivity, indicating
that the (Co1-xNix)Pt3 alloy film with x=0.33 can be used
for practical MO applications. Further increase of Ni content decreases the
θK significantly and destroys the PMA. XRD and AFM studies show
that adding a small amount of Ni in the CoPt3 alloy film will promote
the growth of grains and roughen the film surface, and thus enhance the
coercivity of the film. We observe also that both the coercivity and PMA are
not sensitive to the (111) preferred orientation of the (Co1-xNix
)Pt3 alloy films. 相似文献
18.
19.
用无铅助熔剂法生长了掺铟的铋钙钒铁石榴石(Bi3-2xCa2xFe5-x-yInyVxO12单晶,采用本文所述的助熔剂,均长出了线度在10mm以上的晶粒完整、包容物很少的高质单晶。选用x=0.90,y=0.12的单晶,在0.7—2.2μm波长范围内测量了法拉第磁光旋转角θF和光吸收系数α。我们的结果表明无铅In-BCVIG单晶是磁光优值(M=(│θ关键词: 相似文献
20.
K. Aggarwal L. Asch F. N. Gygax O. Hartmann G. M. Kalvius A. Kratzer F. J. Litterst K. Mattenberger A. Schenck O. Vogt 《Hyperfine Interactions》1989,51(1-4):933-942
The materials crystallize in the NaCl structure. UP undergoes at 122 K a first order transition into a type I single-k antiferromagnetic
state, followed by a second first order transition into a type I double-k-structure at 22 K. UTe is a ferromagnet withT
c
=104 K. The two first order transitions of UP reveal themselves by abrupt changes of the transverse field damping rate. No
spin rotation is observed in zero field for both antiferromagnetic spin structures which is in keeping with point dipolar
lattice sums. In UTe we observe the characteristic critical behavior: a rapid increase of damping rate and paramagnetic frequency
shift when approachingT
c
from above. In the ferromagnetic regime the spin rotation in zero field damps out too rapidly to be observed.
This work has been funded in part by the German Federal Minister for Research and Technology (BMFT) under contract Nr. 03-KA1-TUM-4. 相似文献