93 research outputs found
Muon-spin-rotation measurements of the penetration depth in Li_2Pd_3B
Measurements of the magnetic field penetration depth in the ternary
boride superconductor LiPdB ( K) have been carried out by
means of muon-spin rotation (SR). The absolute values of , the
Ginzburg-Landau parameter , and the first and the second
critical fields at T=0 obtained from SR were found to be
nm, , mT, and
T, respectively. The zero-temperature value of the
superconducting gap 1.31(3) meV was found, corresponding to the
ratio . At low temperatures saturates and
becomes constant below , in agreement with what is expected for
s-wave BCS superconductors. Our results suggest that LiPdB is a s-wave
BCS superconductor with the only one isotropic energy gap.Comment: 6 pages, 7 figure
Probing the Yb spin relaxation in YYbBaCuO by Electron Paramagnetic Resonance
The relaxation of Yb in YBaCuO () was studied
using Electron Paramagnetic Resonance (EPR). It was found that both electronic
and phononic processes contribute to the Yb relaxation. The phononic
part of the relaxation has an exponential temperature dependence, which can be
explained by a Raman process via the coupling to high-energy (500 K)
optical phonons or an Orbach-like process via the excited vibronic levels of
the Cu ions (localized Slonczewski-modes). In a sample with a maximum
oxygen doping =6.98, the electronic part of the relaxation follows a
Korringa law in the normal state and strongly decreases below .
Comparison of the samples with and without Zn doping proved that the
superconducting gap opening is responsible for the sharp decrease of Yb
relaxation in YBaCuO. It was shown that the electronic
part of the Yb relaxation in the superconducting state follows the same
temperature dependence as Cu and O nuclear relaxations despite
the huge difference between the corresponding electronic and nuclear relaxation
rates.Comment: 8 pages, 6 figure
An Analytical Model for Calculation of the Steel Hardness after Continuous Cooling
A number of modern engineering steel grades were analyzed using the CCT diagrams plotted by means of the dilatometer. The statistical analysis of the experimental data allowed for the determination of the equations connecting the critical cooling rate to achieve fully martensitic microstructure and the martensite hardness with the chemical composition of the steel. The dependence of the steel hardness on the cooling rate in the range of 0.1...30 C/s was determined. It was shown that this dependence had the logarithmic character for every studied steel grade. The equations connecting the coefficients of the logarithmic function with the chemical composition of steel were obtained. © Published under licence by IOP Publishing Ltd.The work was supported by the Act 211 of Government of the Russian Federation, contract № 02.A03.21.0006, the Ministry of Science and Higher Education of the Russian Federation, project №11.1465.2014/K, and by the state assignment of the M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, theme “Laser”
Nodeless superconductivity in the infinite-layer electron-doped Sr_0.9La_0.1CuO_2 cuprate superconductor
We report on measurements of the in-plane magnetic penetration depth
\lambda_{ab} in the infinite-layer electron-doped high-temperature cuprate
superconductor Sr_0.9La_0.1CuO_2 by means of muon-spin rotation. The observed
temperature and magnetic field dependences of \lambda_{ab} are consistent with
the presence of a substantial s-wave component in the superconducting order
parameter in good agreement with the results of tunneling, specific heat, and
small-angle neutron scattering experiments.Comment: 6 pages, 5 figure
Dilatometric Research of Cr–Ni–Mo Steels during Isothermal Treatment
В проведенной работе дилатометрическим методом были исследованы Cr-Ni-Mo сталь исходного состава, а также стали с добавлением алюминия и кремния. Определены структура сталей в ходе изотермической обработки, а также влияние на структуру алюминия и кремния.In this work, Cr–Ni–Mo steel of the initial composition and alloyed with aluminum and silicon were investigated by the dilatometric method. The structure of steels during isothermal treatment, as well as the effect on the structure of aluminum and silicon, have been determined
Mixed order parameter symmetries in cuprate superconductors
The recent observation of an inflection point in the temperature dependence
of the in-plane magnetic field dependence (lambda_ab) is investigated within a
two-band model with coupled order parameters of different symmetries. While the
dominant order parameter has d-wave symmetry, the smaller one is of s-wave
symmetry. Superconductivity is robust in the d-wave channel and induced via
interband interactions in the s-wave subsystem.Comment: 10 pages, 4 figure
Oxygen isotope effect on superconductivity and magnetism in Y_1-xPr_xBa_2Cu_3O_7-\delta
Oxygen isotope (^{16}O/^{18}O) effects (OIE's) on the superconducting
transition (T_c), the spin-glass ordering (T_g), and the antiferromagnetic
ordering (T_N) temperatures were studied for Y_1-xPr_xBa_2Cu_3O_7-\delta as a
function of Pr content (0.0\leq x \leq 1.0). The OIE on T_c increases with
increasing x up to x\approx0.55, where superconductivity disappears. For
decreasing x the OIE's on T_N and T_g increase down to x\approx 0.7 where
antiferromagnetic order and down to x\approx0.3 where spin-glass behavior
vanish, respectively. The OIE's on T_g and T_N are found to have {\it opposite
signs} as compared to the OIE on T_c. All OIE's are suggested to arise from the
isotope dependent mobility (kinetic energy) of the charge carriers.Comment: 5 pages, 3 figures, 1 tabl
Effect of Heat Treatment on Microstructure and Properties of High-Strength Steel
Изучены особенности структурообразования в стали 30Х2ГСН2ВМ (ВЛ-1) при реализации различных режимов изотермической обработки: ступенчатая закалка при температуре ниже Мн (quenching-partitioning), изотермическая закалка на бейнит. Показано, что расчетная оптимальная температура ступенчатой закалки не обеспечивает предсказанное количество стабильного остаточного аустенита в структуре исследуемой стали.The microstructure formation in steel 30Kh2GSN2VM are studied after the isothermal treatment: quenching-partitioning, austempering. It is shown that the calculated partitioning temperature does not provide the predicted amount of stable retained austenite in the structure of the steel under study.Исследование выполнено за счет средств гранта Российского научного фонда 22-29-00106.The research was carried out at the expense of the grant of the Russian science foundation 22-29-00106
The Effect of the Tempering Temperature on the Mechanical Properties of the Novel High Strength Steel
The novel high strength steel with high hardenability was studied. The temperature ranges of the austenite transformation were determined. The microstructure and the mechanical properties of the steel under consideration were investigated after the oil quenching and tempering at 200…600 °C.Исследована высокопрочная сталь, обладающая высокой устойчивостью переохлажденного аустенита к превращению по первой ступени. Установлены температурные интервалы превращений при непрерывном нагреве и охлаждении. Исследована микроструктура и определены механические свойства стали после закалки в масле и отпуска в интервале 200…600 °C
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