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1.
The barium strontium titanate ceramics Ba1 − x
Sr
x
TiO3 with a spatially variable composition has been prepared according to the thick film technology (tape casting). The strontium
content over the film thickness is varied from 0 to 30 mol %. The structure and polarization characteristics of the samples
prepared have been investigated. It has been found that the polarization characteristics of multilayer structures are determined
by the ratio between the thicknesses of layers with different compositions and by their properties. No shift of the hysteresis
loops in the graded thick Ba1 − x
Sr
x
TiO3 (
x
= 0–0.3) films has been revealed. The results obtained have been analyzed in the framework of modern theoretical approaches. 相似文献
2.
M. M. Markina K. V. Zakharov A. N. Vasil’ev I. Balasz I. Deac E. Burzo 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(2):190-192
The thermodynamic and magnetic properties of the La1 − x
Pb
x
MnO3 (0.24 ≤ x ≤ 0.40) solid solution system were investigated in the temperature range of 4.2–340 K. All objects were ferromagnetics with
Curie temperature T
C
≈ 320–340 K, which slowly increased with x. The M(T) behavior in the magnetic ordering region indicated a nonuniform ground state, due possibly to the competition of ferromagnetic
and antiferromagnetic interactions. The increase in the saturation magnetic moment with x can be described by a simple model of the binary bonds in La1 − x
Pb
x
MnO3. 相似文献
3.
M. V. Gorev I. N. Flerov V. S. Bondarev M. Maglione A. Simon 《Physics of the Solid State》2011,53(10):2073-2079
The strain, the thermal expansion coefficient, and the permittivity of ceramic samples of (Ba1 − x
Bi2x/3)TiO3 solid solutions with x = 0, 0.01, 0.03, and 0.05 have been studied in the temperature range 120–700 K. Based on an analysis of the results, the
temperature-composition phase diagram has been refined, and the temperature dependence of the polarization has been calculated. 相似文献
4.
Epitaxial thin films of Ba x Sr1 ? x TiO3 solid solutions on MgO(001) and NdGaO3(011) single-crystal substratesare prepared by radio-frequency cathode sputtering of a ceramic target with stoichiometric composition on a magnetron-sputtering apparatus. The main qualitative differences in optical, structural, and electrical properties of the ferroelectric films prepared are determined, and their substantial dependence on the choice of the substrate is revealed. 相似文献
5.
O. A. Savinskaya A. P. Nemudry A. N. Nadeev S. V. Tsybulya N. Z. Lyakhov 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(8):1053-1054
The structure of high-temperature SrFe1 − x
Mo
x
O3 − z
(0 ≤ x ≤ 0.5) phases was studied. Such studies are necessary to understand the mechanism of oxygen transport in membrane materials
used for high-temperature oxygen separation. 相似文献
6.
Qian Wan KuiJuan Jin QingQing Li YaQing Feng Can Wang Chen Ge Meng He HuiBin Lu HaiZhong Guo XiaoLong Li YuPing Yang GuoZhen Yang 《中国科学:物理学 力学 天文学(英文版)》2017,60(5):057711
We investigated the effects of oxygen vacancies on the structural, magnetic, and transport properties of La1–x Sr x MnO3 (x=0.1, 0.2, 0.33, 0.4, and 0.5) grown around a critical point (without/with oxygen vacancies) under low oxygen pressure (10 Pa) and high oxygen pressure (40 Pa). We found that all films exhibit ferromagnetic behavior below the magnetic critical temperature, and that the films grown under low oxygen pressures have degraded magnetic properties with lower Curie temperatures and smaller magnetic moments. These results show that in epitaxial La1–x Sr x MnO3 thin films, the magnetic and transport properties are very sensitive to doping concentration and oxygen vacancies. Phase diagrams of the films based on the doping concentration and oxygen vacancies were plotted and discussed. 相似文献
7.
A. M. Aliev A. G. Gamzatov A. B. Batdalov A. S. Mankevich I. E. Korsakov 《Journal of Experimental and Theoretical Physics》2011,112(3):460-468
A technology for obtaining single-phase ceramic samples of La1 − x
K
x
MnO3 manganites, as well as the dependence of their structure parameters on the potassium content, is described. The magnetocaloric
effect in the samples has been measured by two direct methods, the classical method and the magnetic field modulation method,
and has been calculated from the specific heat data. The values of the magnetocaloric effect obtained by these methods are
significantly different. The observed discrepancies have been explained. Correlation between the doping level and the value
of the effect has been found. It has been shown that the magnetic-field dependence of variation of the magnetic entropy near
T
C in weak fields corresponds to theoretical calculations and that the value of the magnetocaloric effect in high magnetic fields
can be predicted using this dependence. 相似文献
8.
S. S. Aplesnin V. V. Kretinin A. M. Panasevich K. I. Yanushkevich 《Physics of the Solid State》2017,59(4):667-673
The capacitance, inductance, and dissipation factor of the Gd x Bi1–x FeO3 films were measured in the temperature range of 100 K < T < 800 K in magnetic fields of up to 8 kOe at frequencies of 0.1–100 kHz. The magnetic susceptibility maxima in the low-temperature region and dependences of the relaxation time and inductance on prehistory of the films cooled in zero and nonzero magnetic fields are established. The giant increase in magnetic capacitance in the external bias electric field is found. The results obtained are explained by the domain structure transformation in external electric and magnetic fields. 相似文献
9.
V. V. Afrosimov R. N. Il’in S. F. Karmanenko V. I. Sakharov I. T. Serenkov 《Physics of the Solid State》2003,45(6):1122-1127
The initial stages in the growth of BaxSr1?xTiO3 films on various dielectric substrates were studied using the middle-energy ion scattering spectroscopy, and the results obtained were used to analyze microdefects in the film. The character of film growth was found to depend on the shape, size, and electrostatic state of crystallographic unit cells of the substrate surface. The growth was epitaxial on an SrTiO3 substrate. The film prepared on an LaAlO3 substrate consists of slightly disordered crystallites. Films on MgO substrates demonstrated island-type growth up to a thickness of 20 nm, with foreign phases observed to form; as the film thickness increased, the growth acquired an epitaxial pattern. The film grown on the \(\alpha - Al_2 O_3 (1\bar 102)\) surface was polycrystalline and contained textured blocks. 相似文献
10.
G. S. Patrin V. V. Beletskiĭ N. V. Volkov D. A. Velikanov O. V. Zakieva 《Journal of Experimental and Theoretical Physics》2007,105(1):1-3
The results of experimental investigation of magnetic and electric properties of Fe1?x Dy x Si crystals are reported. It is shown that the magnitude and position of the anomaly observed in the temperature dependences of magnetization are controlled to a considerable extent by the external magnetic field. It is found that the introduction of Dy ions leads to a weak magnetoresistive effect. 相似文献
11.
N. I. Kourov A. V. Korolev Yu. V. Knyazev E. G. Gerasimov M. A. Korotin 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(8):1066-1068
Complex investigation of the properties of PdMn x Fe1? x ternary alloys with interacting magnetic and structural order parameters has been performed. It is shown that the complex structural and magnetic state near the transition from the atomically ordered PdFe ferromagnet to the intermetallic antiferromagnetic PdMn compound leads to unusual features not only in magnetic and lattice characteristics but also in electronic properties. 相似文献
12.
S. V. Trukhanov M. V. Bushinsky I. O. Troyanchuk H. Szymczak 《Journal of Experimental and Theoretical Physics》2004,99(4):756-765
The structural, magnetic, and electrotransport properties of La1?xSrxMnO3? x/2(0≤x≤0.30) manganites with perovskite structure are investigated experimentally as a function of oxygen deficiency. In the solid solutions La1?xSrxMnO3, a change in the type of symmetry of the unit cell is observed at x=0.125. Samples with x≤0.125 are characterized by an O′-orthorhombic unit cell, whereas samples with x>0.125 are characterized by a rhombohedral unit cell. The structural properties of the anion-deficient solid solutions La1?xSrxMnO3?x/2 are analogous to those of the stoichiometric system. It is assumed that, as the oxygen content decreases, La1? xSrxMnO3?x/2 anion-deficient solid solutions experience a series of successive magnetic phase transformations in the ground state: from an A-type (x=0) antiferromagnet to a cluster spin-glass-type inhomogeneous magnetic state (0.175>x≤0.30) through a two-phase (antiferromagnetic and ferromagnetic) state (0>x≤0.175). The anion-deficient solid solution with x=0.175 has the maximal value of the ferromagnetic component. As the oxygen deficiency increases, the resistivity of La1? xSrxMnO3?x/2 samples first decreases (up to a value of x=0.175), acquiring an activation character, and then increases (up to a value of x=0.30). In this case, none of the anion-deficient solid solutions exhibits a metal-semiconductor transition in the whole range of concentrations considered. A peak of magnetoresistance at a temperature below the point of magnetic ordering is observed only in the sample with x=0.175. The results of experiments carried out with a series of La1?xSrxMnO3?x/2 anion-deficient solid solutions are summarized in the concentration diagrams of the spontaneous magnetic moment and the critical temperature of magnetic phase transitions. Hypothetical magnetic phase states are pointed out. The experimental results obtained can be interpreted in terms of the phase-separation model and the competition between ferromagnetic and antiferromagnetic indirect superex-change interactions. It is assumed that Mn3+-O-Mn3+ indirect superexchange interactions in the orbitally disordered phase are positive in the case of octahedral coordination of manganese ions and are negative when the coordination of at least one Mn3+ ion is pentahedral. 相似文献
13.
E. Sh. Alekperov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2017,11(5):960-962
The formation of the short-range order structure of amorphous nanometer-thick TlIn1–x Sn x Te2 films (х = 0.02–0.09) obtained via vacuum deposition onto substrates of fresh KCl and KJ chips and celluloid at a temperature below Т = 213 K is studied by high-energy electron diffraction. Both freshly deposited films and films held in vacuum (10–2 Pa) at room temperature in darkness for several months are studied. The effect of the tin concentration on the interatomic distances, the coordination numbers, and the time of amorphous phase stability of TlIn1–x Sn x Te2 films due to a great spread in bond lengths and bond angles is established. 相似文献
14.
The optical transmission spectra of epitaxial Hg1 − x
Cd
x
Te films with a gradient of the band gap have been studied experimentally. The possibility of transforming the spectra after
exposure of the samples to a homogeneous magnetic field has been demonstrated. This effect is possibly caused by the dependence
of the magnetization of the Hg1 − x
Cd
x
Te films on the composition gradient of the solid solution. 相似文献
15.
S. S. Aplesnin L. I. Ryabinkina O. B. Romanova D. A. Velikanov A. D. Balaev D. A. Balaev K. I. Yanushkevich A. I. Galyas O. F. Demidenko O. N. Bandurina 《Journal of Experimental and Theoretical Physics》2008,106(4):765-772
We have studied the resistivity and thermoelectromotive force (thermo emf) in a temperature range of T = 80–1000 K, the magnetic susceptibility and magnetization in a temperature range of T = 4.2–300 K at an external magnetic field of up to 70 kOe, and the structural characteristics of Co x Mn1?x S sulfides (0 ≤ x ≤ 0.4). Anomalies in the transport properties of these compounds have been found in the temperature intervals ΔT 1 = 200–270 K and ΔT 2 = 530–670 K and at T 3 ~ T N. The temperature dependences of the magnetic susceptibility, magnetization, and resistivity, as well as the current-voltage characteristics, exhibit hysteresis. In the domain of magnetic ordering at temperatures below the Néel temperature (T N), the antiferromagnetic Co x Mn1?x S sulfides possess a spontaneous magnetic moment that is explained using a model of the orbital ordering of electrons in the t 2g bands. The influence of the cobalt-ion-induced charge ordering on the transport and magnetic properties of sulfides has been studied. The calculated values of the temperatures corresponding to the maxima of charge susceptibility, which are related to a competition between the on-site Coulomb interaction of holes in various subbands and their weak hybridization, agree well with the experimental data. 相似文献
16.
E. S. Artemova V. N. Semenov V. G. Klyuev O. V. Rebenok A. N. Nituta 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(12):1465-1468
The results from studying Cd x Zn1–x S (0.5 ≤ x ≤ 1) films fabricated via pyrolysis from thiourea coordination compounds of cadmium and zinc bromides doped with silver ions having impurity concentrations of 10–7, 10–6, 10–5, 10–4, and 10–3 mol L–1 in sputtered solutions are presented. Films prepared at 400°С have the wurtzite lattice. The bandgap of pure and doped films, determined from absorption spectra near the edge of fundamental absorption, varies linearly from 2.5 to 3.11 eV. An order of magnitude increase in the intensity of luminescence is observed after doping with silver. 相似文献
17.
V. G. Yakovlev V. V. Mikhailin A. Yu. Romanenko O. M. Basovich E. G. Khaikina 《Moscow University Physics Bulletin》2009,64(5):519-522
The luminescent properties of AgLa1 − x
Eu
x
(MoO4)2 (x = 0.1, 0.2, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0) under laser excitation (λ = 337.1 nm) are studied. It is shown that, upon
substitution of Eu3+ for La3+, the symmetry of luminescence centers does not vary. According to the X-ray diffraction data, all samples have scheelite-like
structure; the pattern of variation in volumes of their unit cells counts in favor of the presence of a continuous series
of solid solutions. It is found that an increase in the europium concentration in AgLa1 − x
Eu
x
(MoO4)2 leads to an increase in the luminescence intensity with a maximum at x = 0.9. 相似文献
18.
The influence of Gd doping at La-site on the electrical transport properties and the colossal magnetoresistance of La0.7−x
Gd
x
Sr0.3MnO3 (x=0.00, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70) is studied. The experimental results indicate that the transport
properties exhibit abnormal behavior under high doping condition. Forx=0.50, we find that a transition from metal to insulator occurs after the occurrence of insulator-metal transition nearT
c, which seldom occurs in ABO3 structure. For samplesx=0.60 and 0.70, it exhibits insulator behavior far aboveT
c. These abnormal behaviors are attributed to different magnetic background, i.e. the system undergoes a transition from long
range ferromagnetic order to the cluster-spin glass state and further to antiferromagnetic order. 相似文献
19.
G. M. Abramova G. Petrakovskiy R. Zuberek A. Nabialek M. Boem V. Sokolov A. F. Bovina 《JETP Letters》2009,90(3):207-210
The magnetostriction of Fe
x
Mn1 − x
S (x = 0.27) single crystals in strong magnetic fields up to 120 kOe has been investigated. It has been found that the magnetostriction
reaches colossal values (±3 × 10−4) atypical of compounds of 3d elements. It has been found that the magnetostriction changes sign when varying temperature and magnetic field; this behavior
indicates an important role of the spin-phonon interactions in the formation of the magnetic order in solid solutions of iron-manganese
sulfides. 相似文献
20.
The heat capacity of pseudobinary intermetallic compounds Gd1−x
Y
x
Ni2 (0≤x≤1) has been studied. The magnetic contribution to the total heat capacity is isolated with the use of the data obtained for
the paramagnetic analogs Lu1−y
Y
y
Ni2 possessing the same molar masses as the gadolinium compounds. It has been found that the difference between the entropies
of the Gd1−x
Y
x
Ni2 (x<0.8) compounds and the corresponding paramagnetic Lu1−y
Y
y
Ni2 analogs reaches larger values than those expected from the calculations performed under the assumption that only Gd ions
contribute to the magnetic part of the total entropy. The existence of an additional contribution of magnetic nature to the
entropy of the Gd1−x
Y
x
Ni2 compounds, as well as the large values of the γ coefficient in the linear-in-temperature term of the heat capacity, is assigned
to the spin fluctuations induced by the f—d exchange in the subsystem of Ni 3d electrons. 相似文献