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1.
The magnetic properties of annealed Fe-Pt multilayer thin films with a broad composition range were investigated in order to identify the effects of composition and annealing temperature on the achievable coercive field, and to identify its maximum at low processing temperatures. Two types of multilayer systems were deposited as materials libraries to vary the composition from Fe20Pt80 to Fe75Pt25. The first type of multilayer was comprised of alternating opposing wedges, whereas the second type consisted of repeated uniform Fe and Pt layers interspersed periodically with Fe wedge layers. It was found that coercive fields μ0HC > 0.7 T can be achieved at an annealing temperature of about 300 °C (60 min) for both types of multilayers as long as the composition is close to 50:50. Higher annealing temperatures are needed for films, which deviate from this composition. Increasing the annealing temperature up to 700 °C leads to increased coercivity values. Multilayers with additional Fe layers showed increased remanence but reduced coercive fields. 相似文献
2.
The IR absorption spectrum of polycrystalline 4-amyloxy-4′-cyanobiphenyl (5OCB) is measured in a KBr pellet over the range 400–4000 cm?1. The structure of the molecule and the frequencies and intensities of the bands in the spectrum are calculated in the approximation of the B3LYP hybrid density functional with the 6-31G(d) and 6-31+G(d) basis sets. With the method of linear scaling of frequencies, 39 bands of the experimental IR spectrum are assigned. On the basis of calculations for related compounds, the vibrations belonging to the substituents and the biphenyl fragment are ascertained. It is shown that the IR absorption spectra of polycrystalline 4-hydroxypropyl-4′-cyanobiphenyl and 5OCB are almost identical and differ by the occurrence of three bands associated with vibrations localized on the oxyamyl radical. 相似文献
3.
A. P. Kilimov M. A. Svechnikova V. I. Shevchenko V. V. Smirnov F. V. Kvasnyuk-Mudryi S. B. Zotov 《Chemistry of Heterocyclic Compounds》1967,3(2):467-471
Data for the characteristic bands of cyclic ethers are reviewed. The infrared spectra of a number of 2-mono- and 2, 5-di-substituted
derivatives of tetrahydrofuran are investigated. Absorption bands at about 900 cm−1 are related to pulsation vibrations, and those at about 1200 cm−1 to antisymmetric skeletal vibrations, of the tetrahydrofuran ring. It is shown that to confirm the presence of a tetrahydrofuran
ring in a molecule, it is necessary to take into account not only the band of valence antisymmetric vibrations of the group
C-O-C (ν
C-O-C
as
1075 cm−1), but also bands due to ring pulsation vibrations (ring symmetric valence vibrations ν
sk
s
∼ 900 cm1). 相似文献
4.
A. P. Kilimov M. A. Svechnikova V. I. Shevchenko V. V. Smirnov S. B. Zotov F. V. Kvasnyuk-Mudryi 《Chemistry of Heterocyclic Compounds》1969,5(2):156-159
The IR spectra of six monosubstituted and of four 2,6-disubstituted 1,4-dioxanes have been studied in the 650–1800cm–1 region. The assignment of the bands due to the vibrations of the 1,4-dioxane ring and to the deformation vibrations of the methylene groups of the ring is given. The appearance of a whole series of new absorption bands on passing from unsubstituted 1,4-dioxane to its derivatives is explained by the change in the symmetry of the molecule and the removal of the prohibition from the vibrations previously inactive in the IR spectra connected with this reduction in symmetry. It is proposed to use, in order to confirm the presence of a 1,4-dioxane ring in a molecule from the results of IR spectroscopy, not only the 1126-cm–1 band but the whole group of bands lying in the frequency ranges 800–950, 1000–1150, and 1200–1300 cm–1.For part I, see [3]. 相似文献
5.
Theoretical and Mathematical Physics - We discuss properties of R-matrix-valued Lax pairs for the elliptic Calogero-Moser model. In particular, we show that the family of Hamiltonians arising from... 相似文献
6.
A. V. Zotov N. N. Akinfiev L. A. Koroleva 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(8):1259-1265
Values of the pH for four solutions in a KHPh-HCl-KOH system, where Ph denoting C8O4H4, are measured at 25–70°C depending on pressure (1–1000 bar). The experimental results and the available literature data are processed on the base of Helgeson-Kirkham-Flowers (HKF) equation of state [1] and the GIBBS, OptimA, and OptimB programs from the HCh software package [2]. The obtained standard thermodynamic properties and HKF parameters of H2Phaq, HPh?, and Ph2? aqueous species, provides calculation of the pH of phthalate buffers in a wide range of temperatures (up to 200°C) and pressures (up to 5 kbar). The calculated values for the biphthalate buffer (0.05m KHPh) correspond to the IUPAC recommendations (at 0–50°C and 1 bar) with an accuracy of 0.005 pH units, and to the values of pH measured in this study at elevated Tp parameters (25–70°C and pressures of up to 1 kbar) within the limits of ±0.02 pH units. 相似文献
7.
N. I. Solin L. N. Romashev S. V. Naumov A. A. Saranin A. V. Zotov D. A. Olyanich V. G. Kotlyar O. A. Utas 《Technical Physics》2016,61(2):233-239
We consider methods for controlling magnetoresistive parameters of magnetic metal superlattices, manganites, and magnetic semiconductors. By reducing the thickness of ferromagnetic layers in superlattices (e.g., Fe layers in Fe/Cr superlattices), it is possible to form superparamagnetic clustered–layered nanostructures with a magnetoresistance weakly depending on the direction of the external magnetic field, which is very important for applications of such type of materials. Producing Mn vacancies and additionally annealing lanthanum manganites in the oxygen atmosphere, it is possible to increase their magnetoresistance by more than four orders of magnitude. By changing the thickness of p–n junction in the structure of ferromagnetic semiconductors, their magnetoresistance can be increased by 2–3 orders of magnitude. 相似文献
8.
A method for reconstruction of the laser beam phase from shearing interferograms using separation of the amplitude and phase parts of the spatial spectrum is proposed and tested both numerically and experimentally with a laboratory model of the turbulent atmosphere, which allows purposefully varying the state of turbulence and controlling its parameters. Amplitude-phase correlation in the fluctuation structure of the laser beam that passed through turbulent medium is investigated. The recorded correlation coefficient typical of weak fluctuations varies in the range of 0.2 to 0.3. 相似文献
9.
A.?A.?Alekseev D.?A.?Olyanich T.?V.?Utas V.?G.?KotlyarEmail author A.?V.?Zotov A.?A.?Saranin 《Technical Physics》2015,60(10):1508-1514
Scanning tunneling microscopy (STM) is used to study the basic laws of growth of ultrathin epitaxial CoSi2(111) films with Co coverages up to 4 ML formed upon sequential deposition of Co and Si atoms taken in a stoichiometric ratio onto the Co–Si(111) surface at room temperature and subsequent annealing at 600–700°C. When the coverage of Co atoms is lower than ~2.7 ML, flat CoSi2 islands up to ~3 nm high with surface structure 2 × 2 or 1 × 1 grow. It is shown that continuous epitaxial CoSi2 films containing 3–4 triple Si–Co–Si layers grow provided precise control of deposition. CoSi2 films can contain inclusions of the local regions with (2 × 1)Si reconstruction. At a temperature above 700°C, a multilevel CoSi2 film with pinholes grows because of vertical growth caused by the difference between the free energies of the CoSi2(111) and Si(111) surfaces. According to theoretical calculations, structures of A or B type with a coordination number of 8 of Co atoms are most favorable for the CoSi2(111)2 × 2 interface. 相似文献
10.
V. A. Burov O. V. Matveev D. I. Zotov O. D. Rumyantseva 《Physics of Wave Phenomena》2015,23(2):135-142
The possibility of simultaneous reconstruction of the blood flow velocity vector and spatial distributions of the speed of sound and absorption coefficient in a medical ultrasonic tomograph is discussed. The operating capacity of the proposed spatial-correlation method for determining the blood flow velocity vector is confirmed by experiments on a tomograph prototype. 相似文献