共查询到20条相似文献,搜索用时 31 毫秒
1.
V. Venkataramanan K. Noguchi M. Aono T. Suzuki 《Applied physics. B, Lasers and optics》2002,74(7-8):683-689
We describe the instrumentation related to the first observation of magnetization-induced enhancement of surface second-harmonic
generation (SHG) from the paramagnetic Si(111)-7×7 surfaces. A judicious choice of polarization and sample orientation enabled
us to isolate the magnetic-field-dependent tensor element of the nonlinear susceptibility. A conductive liquid-nitrogen system,
coupled to an ultrahigh-vacuum system that is immune to the high magnetic field of 10 T, cooled the sample to about 120 K.
A high extinction that is necessary to detect the magnetization-induced SHG (MSHG) was accomplished by minimizing stray optical
effects such as Faraday rotation, photoluminescence and thermal birefringence in all optical components, with extra care taken
for the UHV window. Consistent and stable operation of this sensitive measurement system permitted experiments involving MSHG
at multiple wavelengths and temperatures. Probing the magnetization-induced optical nonlinearity was validated by quenching
the surface states by oxidation of the surface layers. From MSHG measurements at two wavelengths resonant with different surface-state
transitions, we were able to suggest that the observed MSHG is proportional to the number of dangling bond states of Si(111)-7×7.
Received: 15 January 2002 / Published online: 2 May 2002 相似文献
2.
T. V. Murzina I. A. Kolmychek A. I. Maydykovskiy 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(2):174-176
Features of the second- and third-order nonlinear effects in composite plasmonic core/shell nanoparticles placed into a polymer
matrix are investigated. Resonant enhancement of the effective third-order susceptibility is observed, as well as the appearance
of a coherent magnetization-induced component of the second harmonic. 相似文献
3.
T.V. Murzina I.E. Razdolski A.M. Grishin 《Journal of magnetism and magnetic materials》2009,321(7):836-839
Nonlinear magneto-optical properties of all-garnet magnetophotonic crystals composed of alternating layers of ferromagnetic Bi3Fe5O12 (BIG) and Sm3Ga5O12 quarter-wavelength layers with a half-wavelength BIG microcavity mode are presented. The samples are grown by rf-magnetron sputtering on non-magnetic GGG substrate. Many-fold enhancement of the magnetization-induced effects in second-harmonic generation (SHG) as compared with linear magneto-optical effects are observed: the SHG magnetic contrast up to 50% and magnetization-induced rotation of the polarization plane of about 90° are measured at the resonance microcavity wavelengh of λ=779 nm. 相似文献
4.
T. V. Murzina E. M. Kim S. E. Matskevich O. A. Aktsipetrov A. F. Kravets A. Y. Vovk 《JETP Letters》2004,79(4):155-159
Magnetization-induced third harmonic (TH) generation was observed in magnetic nanostructures—nanogranular CoxAg1? x films—possessing giant magnetoresistance (GMR). The magnetization-induced contribution to the TH intensity was studied as a function of the concentration of a magnetic component (cobalt) in the films. Magnetic contrast of the TH intensity was found to correlate with the GMR coefficient: both parameters simultaneously reach extremum in the range of cobalt concentrations x~0.3–0.35. 相似文献
5.
K. Napolskii A. Eliseev A. Rubacheva M. Kuznetsov V. Valdner A. van Etteger 《Journal of magnetism and magnetic materials》2009,321(7):833-835
Nickel inverse opals were fabricated by templating a colloidal crystal. Perfect fcc ordering was confirmed by scanning electron microscopy. Several kinds of magneto-optical effects were studied: linear longitudinal and transversal Kerr effects, nonlinear longitudinal Kerr effect (magnetization-induced second harmonic generation), which were all consistent with the photonic band structure studied by reflectivity spectroscopy. 相似文献
6.
Magnetization-induced optical surface second harmonic generation (SHG) in the longitudinal geometry was used to study magnetism on the p(1 x 1)O/Fe(001) surface during a layer-by-layer Fe growth with surfactant oxygen. Considerable one-monolayer oscillations were observed. Minima of the magnetization-induced contributions to the second order dielectric susceptibility were detected at half-filled monolayers. These contributions were accessed either by measuring a purely magnetic SHG yield, or indirectly from the magnetization dependence of the overall SHG signal, both providing consistent results. The origin of the oscillatory surface magnetism is consistent with the expected oscillating oxygen induced relaxation due to the surface Fe islands. 相似文献
7.
8.
Spectroscopic magnetization-induced optical second harmonic generation (MSHG) measurements from a clean Ni(110) surface reveal strong resonance effects near 2.7 eV that can be attributed to the presence of an empty surface state. The good agreement with model calculations shows the potential of MSHG to probe spin-polarized interface band structures. 相似文献
9.
10.
Zhao HB Talbayev D Lüpke G Hanbicki AT Li CH van't Erve MJ Kioseoglou G Jonker BT 《Physical review letters》2005,95(13):137202
The reversal process of the Fe interface layer magnetization in Fe/AlGaAs heterostructures is measured directly using magnetization-induced second-harmonic generation, and is compared with the reversal of the bulk magnetization as obtained from magneto-optic Kerr effect. The switching characteristics are distinctly different due to interface-derived anisotropy--single step switching occurs at the interface layer, while two-jump switching occurs in the bulk Fe for the magnetic field orientations employed. The angle between the interface and bulk magnetization may be as large as 40-85 degrees. Such interface switching will dominate the behavior of nanoscale structures. 相似文献
11.
Second harmonic generation (SHG) induced by spontaneous magnetization has been investigated for a polar ferromagnetic crystal of GaFeO3. The Kerr rotation of the second harmonic light becomes gigantic with decreasing temperature below the magnetic transition temperature (approximately =205 K), e.g., as large as 73 degrees at 100 K. The magnetic domains can be visualized by using that large nonlinear Kerr rotation. The spectrum of the magnetization-induced SHG as measured indicates the two-photon resonant electronic process on a Fe3+ ion in the crystal. 相似文献
12.
The magnetization-induced nonlinear optical and nonlinear magneto-optical properties in a magnetic metal-insulator composite are studied based on a tensor effective medium approximation with shape factor and Taylcr-expansion method. There is a weakly nonlinear relation between electric displacement D and elcctric field E in the composite. The results of our studies on the effective dielectric tensor and the nonlinear susceptibility tensor in a magnetic nanocomposite are surveyed. It is shown that such a metal-insulator composite exhibits the enhancements of optical and magneto-optical nonlinearity. The frequencies at which the enhancements occur, and the amplitude of the enhancement factors depend on the concentration and shape of the magnetic grains. 相似文献
13.
This overview summarizes important aspects of the cantilever stress measurement technique and its application to measurements
of adsorbate-induced surface stress changes and magnetization-induced magnetoelastic stress (also called magnetostrictive
stress) of ferromagnetic monolayers. The application of the cantilever technique as a torque magnetometer with monolayer sensitivity
is demonstrated. The stress measurements indicate a correlation between surface stress changes and surface reconstruction,
and they also identify the often decisive role of the magnetoelastic anisotropy for the non-bulklike magnetic anisotropy of
ferromagnetic monolayers.
PACS 68.35.Gy; 68.35.Bs; 75.70.Ak; 75.80.+q 相似文献
14.
15.
V. F. Shkar’ V. P. Denisenkov A. M. Grishin A. A. Yalali S. I. Khartsev E. I. Nikolaev V. N. Sayapin 《Physics of the Solid State》2003,45(12):2334-2337
Bismuth iron garnet films prepared through electron-beam and laser-induced evaporation on (001)-oriented substrates of scandium gallium gadolinium garnet are investigated using ferromagnetic resonance. It is assumed that the additional minima observed in the angular dependence of the resonance field can be associated with the magnetic moment of bismuth ions. 相似文献
16.
J. Rogel-Salazar 《Contemporary Physics》2013,54(4):385-386
Measurements of the Faraday magneto-optical effect and of optical absorption in magnetic garnet crystals and films are reviewed. Earlier work was restricted to measurements in the visible spectrum; these measurements showed that the transparency was sufficient to allow magnetic domains to be studied in relatively thick slabs. Within the last year or so interest has been renewed in extending magneto-optical measurements beyond the visible spectrum. In particular, extremely low absorptions are found in the wavelength range of approximately 1–5 microns. Thie work is, in no small way, spurred by the possibility of developing a light-beam modulator using the Faraday effect in this wavelength range. Recent measurements at very short wavelengths using garnet films are also reported. By extending the short wavelength measurements to 3000 Å, about two orders of magnitude increase in Fareday rotation and optical absorption are observed, compared with the visible spectrum measurements. The Faraday effect has been used to measure magnetic hysteresis loops in single-crystal garnet slabs. Magneto-optical observation of the corresponding domain structures shows them to be particularly simple. Detailed correlation of domain structure and hysteresis loops is described; in addition, an estimate of the domain wall energy and its width is made from these measurements. The garnets referred to in this review are yttrium iron garnet (YIG), gadolinium iron garnet (GdIG), and YIG doped with gallium (YGaIG). 相似文献
17.
Crystal growth and the magnetic properties of bismuth substituted yttrium iron garnet (Bi-YIG) nanoparticles were studied with particular focus on the bismuth composition dependence of the magnetic properties of the particles and the effects of annealing on the garnet phase formation. The Bi-YIG nanoparticles of 47–67 nm in size can be chemically synthesized when they are annealed at 650–850 °C. Both the lattice constant and the magnetization of the garnet nanoparticles linearly increase when the bismuth composition in the Bi-YIG particles increases. We have found that chemically synthesized nanoparticles transform from the amorphous to the garnet phase when annealed at temperatures below 650 °C, while the onset of magnetic moment of iron in the garnet nanoparticles is observed slightly above 650 °C. According to Mössbauer effect measurements, the hyperfine fields of 57Fe at the tetrahedral and octahedral sites in the garnet are 39 and 48 T, respectively. 相似文献
18.
S. C. Zanatta F. F. Ivashita K. L. da Silva C. F. C. Machado A. Paesano Jr. 《Hyperfine Interactions》2014,224(1-3):307-312
We have investigated the mechanosynthesis of gadolinium iron garnet (GdIG) by high-energy ball-milling of 3.(Gd2O3)?+?10.(α-Fe) followed by thermal annealing conducted at moderate temperatures (1100 °C). The samples were characterized by X-ray diffraction and Mössbauer spectroscopy in order to determine the influence of the milling time on the final products. For as-milled samples the results revealed the enlargement of the magnetic component belonging to iron and a discrete paramagnetic component. The formation of a garnet phase was observed in all as-annealed samples treated at 1100 °C for 6 h in quantities proportional to the time of grinding the precursors. Evidently, high-energy ball milling of Gd2O3?+?α-Fe powders is an important step in GdIG synthesis by a ceramic method. Single-phase garnet is observed for the samples milled for 12 and 24 h treated at 1100 °C for 6 h. 相似文献
19.
P. Röschmann 《Journal of Physics and Chemistry of Solids》1980,41(6):569-581
The temperature dependence of the equilibrium distribution of Ga resp. Al substitutions over the a-and d-sites in single crystal yttrium iron garnet has been determined from magnetization measurements for substitution levels 0 < z < 1.5 and equilibrium temperatures between 773 and 1773 K. Including literature data derived by different experimental methods for as grown samples of various substituted garnet systems with 0 < z < 5 it is shown that the cation distribution observed on single crystals and polycrystalline samples can be well described by a thermodynamic equilibrium distribution model with two stabilizing energies as fitting parameters. The model includes the influence of the level of substitution and of the actual distribution on the effective site stabilizing energy. By a least error fit to the experimental data the two fitting parameters are determined in terms of the site stabilizing energies for the end member garnets with substitution levels z → 0 and z → 5, respectively: 0.272eV and 0.230eV for Ga substituted yttrium iron garnet: 0.178eV and 0.132eV for Al substituted yttrium iron garnet; 0.26 eV and 0.11 eV for Ga substituted yttrium aluminum garnet; 0.20 eV and 0.15eV for Ga substituted europium iron garnet. 相似文献
20.
A. L. Gordon G. A. Melkov A. A. Serga V. S. Tiberkevich A. V. Bagada A. N. Slavin 《JETP Letters》1998,67(11):913-918
Phase conjugation of magnetostatic waves by a local longitudinal pump in yttrium iron garnet films is observed experimentally. Theoretical expressions are obtained which describe the experimental curves well. 相似文献