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1.
E. O. Klebanskii A. Yu. Kudzin V. M. Pasal’skii S. N. Plyaka L. Ya. Sadovskaya G. Kh. Sokolyanskii 《Physics of the Solid State》1999,41(6):913-915
The sol-gel method is used to obtain thin films with the composition Bi12SiO20. The characteristic features of the technology for obtaining the films are presented. Diffractometry confirmed that the films
possess γ-Bi2O3-type structure. The transmission spectra of the films were investigated. The spectral dependence of the absorption coefficient
of the films matches well with the spectra determined using bulk Bi12SiO20 crystals.
Fiz. Tverd. Tela (St. Petersburg) 41, 1003–1005 (June 1999) 相似文献
2.
R. S. Iskhakov Zh. M. Moroz L. A. Chekanova N. A. Shepeta E. E. Shalygina 《JETP Letters》1997,66(7):517-521
It is found that the exchange interaction of Co (5 nm)ferromagnetic layers via Pd in Co/Pd multilayer films and of Co (5 nm)and
CoNi (5 nm) layers via the same nonmagnetic metal in Co/Pd/CoNi films can be both ferro-and antiferromagnetic. The period
of the AF-F-AF oscillations is of the order of 0.8 nm, and the amplitude of the oscillations decays as a power-law function
~d
Pd
−2
.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 7, 487–491 (10 October 1997) 相似文献
3.
E. R. Likhachev S. I. Kurganskii O. I. Dubrovskii A. M. Bugakov 《Physics of the Solid State》1997,39(3):378-380
The results of calculations of the energy band structure of thin films are used to obtain theoretical photoelectron spectra
of the valence band of the compound YBa2Cu3O7−δ
for δ=0 and δ=1 at various photon energies; the spectra are averaged over the photoelectron emission angles. The principal structural features
of the spectra are determined by the d states of copper atoms, while the variation of the shape of the spectra with increasing photon energy is attributed to a
relative decrease in the contribution from the p states of oxygen atoms. The density of d states around the Fermi level for YBa2Cu3O6 films is observed to increase relative to YBa2Cu3O7 films.
Fiz. Tverd. Tela (St. Petersburg) 39, 437–440 (March 1997) 相似文献
4.
S.A. Chambers D.A. Schwartz W.K. Liu K.R. Kittilstved D.R. Gamelin 《Applied Physics A: Materials Science & Processing》2007,88(1):1-5
We have used oxygen plasma assisted metal organic chemical vapor deposition along with wet chemical synthesis and spin coating
to prepare CoxZn1-xO and MnxZn1-xO epitaxial and nanoparticle films. Co(II) and Mn(II) substitute for Zn(II) in the wurtzite lattice in materials synthesized
by both methods. Room-temperature ferromagnetism in epitaxial Co:ZnO films can be reversibly activated by diffusing in Zn,
which occupies interstitial sites and makes the material n-type. O-capped Co:ZnO nanoparticles, which are paramagnetic as
grown, become ferromagnetic upon being spin coated in air at elevated temperature. Likewise, spin-coated N-capped Mn:ZnO nanoparticle
films also exhibit room-temperature ferromagnetism. However, the inverse systems, N-capped Co:ZnO and O-capped Mn:ZnO, are
entirely paramagnetic when spin coated into films in the same way. Analysis of optical absorption spectra reveals that the
resonances Co(I)↔Co(II)+e-
CB and Mn(III)↔Mn(II)+h+
VB are energetically favorable, consistent with strong hybridization of Co (Mn) with the conduction (valence) band of ZnO. In
contrast, the resonances Mn(I)↔Mn(II)+e-
CB and Co(III)↔Co(II)+h+
VB are not energetically favorable. These results strongly suggest that the observed ferromagnetism in Co:ZnO (Mn:ZnO) is mediated
by electrons (holes).
PACS 75.50.Pp 相似文献
5.
The energy gap appearing in the spin-wave spectrum as a result of Bragg scattering by the modulation period q=2π/(d
1+d
2) of a one-dimensional superlattice is observed by the method of spin-wave resonance in Co/Pd multilayer films. It is shown
that this gap is asymmetric: The “positive” deviation is from two to three times greater than the “negative” deviation.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 12, 938–941 (25 June 1996) 相似文献
6.
A. N. Drachenko A. N. Yurasove I. V. Bykov E. A. Gan’shina A. B. Granovskii V. V. Ryl’kov D. V. Smirnov J. Leotin B. Dieny 《Physics of the Solid State》2001,43(5):932-934
The optical absorption spectra of magnetic quasi-2D Co island films and of hybrid Co/SiO2 multilayers in which island films are separated by SiO2 layers were studied. It was found that, when the Co film was masked by a thin SiO2 layer, the absorption considerably increased and exceeded 0.8. This was observed when the Co fraction was substantially lower than its critical value for the percolation transition. Moreover, the maximal absorption in this case weakly depends on both the effective film thickness and the number of Co layers. Numerical analysis shows that the observed peculiarities of the absorption spectra of the structures based on quasi-2D granulated Co films are connected to a great extent with the peculiar features of the interference effects occurring in such systems. 相似文献
7.
Results are presented of the first measurements of infrared reflection spectra of Zn1−x
CdxSe films (x=0–0.55; 1) grown on a GaAs substrate by molecular-beam epitaxy. It is shown by a mathematical analysis of the experimental
spectra that the investigated Zn1−x
CdxSe alloy system manifests a unimodal rearrangement of its vibrational spectrum as the composition is varied.
Fiz. Tverd. Tela (St. Petersburg) 41, 982–985 (June 1999) 相似文献
8.
J.A. Sans J.F. Snchez-Royo J. Pellicer-Porres A. Segura E. Guillotel G. Martinez-Criado J. Susini A. Muoz-Pez V. Lpez-Flores 《Superlattices and Microstructures》2007,42(1-6):226
In this paper, we investigate the Co site configuration in Zn1−xCoxO thin films by means of different spectroscopic techniques. Thin films were prepared by pulsed laser deposition with Co proportion from 1% to 30%. The Co 2p doublet observed in the X-ray photoelectron spectra exhibits the spin–orbit splitting and shake-up satellites typical of Co+2 ionization states. X-ray absorption spectra at the Co K-edge, taken in fluorescence mode, unambiguously show that Co atoms are in tetrahedral configuration substituting for Zn over the whole composition range. Optical absorption spectra provide further evidence of the tetrahedral coordination of Co cations, both through the internal transitions in the Co 3d shell and through the shift to higher energies of the band-to-band absorption edge with the increase of the Co proportion. 相似文献
9.
E.A. Gan'shina A.B. Granovsky N.S. Perov 《Journal of magnetism and magnetic materials》2009,321(7):723-725
We report an experimental study on transversal Kerr effect (TKE) in magnetic oxide semiconductors TiO2−δ:Co. The TiO2−δ: Co thin films were deposited on LaAlO3 (0 0 1) substrates by magnetron sputtering in the argon-oxygen atmosphere at oxygen partial pressure of 2×10−6-2×10−4 Torr. It was obtained that TKE spectra in ferromagnetic samples are extremely sensitive to the Co-volume fraction, the crystalline structure, and technology parameters. The observed well-pronounced peaks in TKE spectra for anatase Co-doped TiO2−δ films at low Co (<1%) volume fraction are not representative for bulk Co or Co clusters in TiO2−δ matrix that indicates on intrinsic ferromagnetism in these samples. With increase of Co-volume fraction up to 5-8% the fine structure of TKE spectra disappears and magneto-optical response in reflection mode becomes larger than that for thick Co films 相似文献
10.
采用脉冲激光气相沉积(PLD)方法,在Si(100)晶面上制备了Co:BaTiO3纳米复合薄膜.采用X射线衍射(XRD)结合透射电镜(TEM)方法研究了两种厚度Co:BaTiO3纳米复合薄膜的晶体结构,当薄膜厚度约为30 nm时,薄膜为单一择优取向;当薄膜厚度约为100nm时,薄膜呈多晶结构.原子力显微镜(AFM)分析表明,当膜厚为30nm时,薄膜呈现明显的方形晶粒.采用紫外光电子能谱(UPS)研究了Co的价态和Co:BaTiO3纳米复合薄 相似文献
11.
采用脉冲激光气相沉积(PLD)方法,在Si(100)晶面上制备了Co:BaTiO3纳米复合薄膜.采用X射线衍射(XRD)结合透射电镜(TEM)方法研究了两种厚度Co:BaTiO3纳米复合薄膜的晶体结构,当薄膜厚度约为30 nm时,薄膜为单一择优取向;当薄膜厚度约为100nm时,薄膜呈多晶结构.原子力显微镜(AFM)分析表明,当膜厚为30nm时,薄膜呈现明显的方形晶粒.采用紫外光电子能谱(UPS)研究了Co的价态和Co:BaTiO3纳米复合薄
关键词:
3')" href="#">BaTiO3
纳米复合薄膜
紫外光电子能谱 相似文献
12.
V. S. Vinogradov L. K. Vodop’yanov S. P. Kozyrev Yu. G. Sadof’ev 《Physics of the Solid State》1999,41(11):1786-1789
The lattice IR reflection spectra of epitaxial ZnSe films are studied for different thicknesses on a (001)GaAs substrate.
The frequency of the TO mode is found to increase for films with thicknesses of 0.8 and 1.2 μm that exceed the critical value d
cr
≈0.1 μm for ZnSe/GaAs pairs. The effect is explained by the existence of regions with residual stress in the film.
Fiz. Tverd. Tela (St. Petersburg) 41, 1948–1952 (November 1999) 相似文献
13.
K. Koike M. Ohtsuka M. Matsumoto Y. Adachi T. Takagi H. Kato 《The European physical journal. Special topics》2008,158(1):143-148
Effects of Fe and Co addition on the magnetoresistance MR were investigated in sputtered Ni-Mn-Ga-M (M = Fe, Co) films. With
increasing M content, magnetization σ enhanced for M = Fe, while it reduced for M = Co. At 300 K, absolute MR value at 1.5 T
|MR|1.5 was about 1%. The value of |MR|1.5 was found to be decreased with increasing M = Fe content. In the case of M = Co, |MR|1.5 increased with M content. |MR|1.5 of the film containing Co 1.6 at.% showed a maximum value of 2.5% at 355 K in the vicinity of the Curie temperature TC. An origin of MR behavior in the present films was suggested to be explained by a s-d scattering model. 相似文献
14.
It is found that photoinduced absorption in the energy range 0.6–2.1 eV in C60 films grown by the same method can differ by a factor of 100. This change is attributable a 106-fold increase in the relaxation time τ of electron-hole photoexcitations after working with the films for several months. It is established that the bimolecular
recombination mechanism for photoexcitations (triplet excitons and polarons), which is typical of as-prepared and partially
aged films, is superseded in fully aged films by thermally activated tunneling of localized photoexcitations. An investigation
of the film transmission spectra in the photon energy range 0.2–5.0 eV shows that the long-time variations of the optical
properties are associated with a decrease in the concentration of defects forming shallow tails of the density of states.
An abrupt decrease of the relaxation time τ and the photoinduced absorption is observed in both types of films at T⩾80 K.
Fiz. Tverd. Tela (St. Petersburg) 39, 1303–1309 (July 1997) 相似文献
15.
N. N. Loshkareva Yu. P. Sukhorukov V. E. Arkhipov S. V. Okatov S. V. Naumov I. B. Smolyak Ya. M. Mukovskii A. V. Shmatok 《Physics of the Solid State》1999,41(3):426-432
To study the band structure and carriers in lanthanum manganites, measurements have been made of the reflectance spectra of
single crystals and polycrystals in the 0.04–1.6-eV range and of the optical conductivity σ
opt calculated by the Kramers-Kronig method as functions of the concentration and species of divalent ions in the paramagnetic
(PM) and ferromagnetic (FM) regions. The optical gap for single-crystal La0.9Sr0.1MnO3 is ∼0.17 eV, and the polaronband energy is 0.12 eV. In the PM region, σ
opt spectra do not indicate a band-carrier contribution, and conduction is dominated by polaron hopping and activation to the
mobility edge. In the FM region, the variation in the σ
opt and absorption spectra of La0.7Sr0.3MnO3 epitaxial films indicate the appearance of band carriers and a red shift of the absorption edge. The two band-carrier contributions,
with weak and strong dependences on photon energy, are related to conduction in the antiferromagnetic matrix and the ferromagnetic
regions.
Fiz. Tverd. Tela (St. Petersburg) 41, 475–482 (March 1999) 相似文献
16.
R. V. Kuz’menko A. V. Ganzha O. V. Bochurova É. P. Domashevskaya J. Schreiber S. Hildebrandt S. Mo E. Peiner 《Physics of the Solid State》1999,41(4):654-659
A study is reported of the structure of photoreflectance (PR) spectra in the vicinity of the E
0 transition from thin (d=1–5 μm) n-GaAs and n-InP films (n=1016–1017 cm−3) grown epitaxially on Si(001) substrates. A quantitative analysis of the spectra involving multi-component fitting shows
that the electronic optical transition from the {3/2;±1/2} subband provides a dominant contribution to the intermediate-field
electromodulation component in both systems. The splitting observed in the GaAS/Si PR spectra near the main peak are accounted
for not by the strain-induced valence-band splitting but rather by a spectral superposition of the intermediate-field component
due to the {3/2;±1/2} subband with a low-energy excitonic component. The analytically established transition energy E
0
3/2;±1/2
is used to calculate biaxial strains in epitaxial films.
Fiz. Tverd. Tela (St. Petersburg) 41, 725–731 (April 1999) 相似文献
17.
S. M. Zharkov V. S. Zhigalov L. I. Kveglis Yu. V. Lisitsa K. V. Renskaya G. I. Frolov 《JETP Letters》1997,65(12):915-918
The process of dendritic crystallization of Co and Fe films is investigated. Electron-diffraction methods show that fractal
growth of dendrites in Co and Fe films proceeds by multiple twinning of the elements of a nanostructure consisting of different
clusters with close-packing. The formation of superstructures is explained by a shell model of a cluster structure forming
nanocrystallites.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 12, 872–875 (25 June 1997) 相似文献
18.
Photoinduced polymerization and photoinduced diffusion of molecular oxygen in thin C60 films irradiated by femtosecond laser pulses are investigated. A comparison of the Raman scattering and absorbed energy spectra
and the irradiation doses required to observe photopolymerization using continuous-wave radiation and femtosecond pulses shows
that the efficiency of both photoinduced processes decreases considerably in the latter case.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 4, 320–325 (25 August 1998) 相似文献
19.
Cobalt-copper films obtained by pulsed electrolytic deposition from a single electrolyte are investigated. The continuous
transition from Co/Cu multilayer films to films of inhomogeneous Cu/Co alloys can be traced on the basis of an x-ray structural
investigation, as well as nuclear magnetic resonance and magnetoresistance measurements. An explanation for the observed phenomena
is proposed.
Zh. Tekh. Fiz. 67, 89–91 (December 1997) 相似文献
20.
The angular dependence of the spin-wave resonance spectra is investigated in multilayer magnetic films in which the spin pinning
mechanism changes from dynamical to dissipative. A fundamental difference is observed in the character of the angular dependences
of the spectra for three-layer films as opposed to two-layer films. In particular, the number of peaks in the spectrum of
three-layer films is observed to decrease and then increase twice as the angle between the magnetic field and the normal to
the film is varied by π/2.
Zh. Tekh. Fiz. 69, 97–101 (November 1999) 相似文献