相关论文: Microwave Harmonic Emission in MgB2 Superconductor…

We report experimental results of second-harmonic (SH) response at microwave frequency in several ceramic MgB2 samples, prepared by different methods. The SH signal has been investigated as a function of the temperature and DC magnetic…

Nonlinear microwave response of different ceramic MgB2 samples has been investigated by the technique of second-harmonic emission. The second-harmonic signal has been investigated as a function of temperature, DC magnetic field and input…

We discuss the microwave second-harmonic generation in high-density bulk MgB2, prepared by the reactive liquid Mg infiltration technology. The intensity of the harmonic signal has been investigated as a function of temperature and…

The microwave response of ceramic MgB2 has been investigated as a function of temperature and external magnetic field by two different techniques: microwave surface impedance and second-harmonic emission measurements. The measurements of…

Relaxation of the microwave second order response of YBa2Cu3O7 and Ba0.6K0.4BiO3 crystals in the critical state is studied. The samples are exposed to static and pulsed microwave magnetic fields. The second harmonic signals decay during the…

Measurements of the temperature dependence of the surface resistance at 3 GHz of 100 micron size grains of MgB_2 separated powder are presented and discussed. The microwave surface resistance data is compared to experimental results of Nb,…

Measurements of the $10GHz$ microwave surface resistance of dense $MgB_{2}$ wire and pellet are reported. Significant improvements are observed in the wire with reduction of porosity. The data lie substantially above the theoretical…

We report experimental evidence of mechanical wave generation by magnetic nanoparticles (MNPs) under radiofrequency electromagnetic fields (EMFs, 65mT, 800 kHz, at 100ms bursts) in the ultrasonic (US) frequency range. We developed an…

We have measured the low-temperature specific heat C(T) for polycrystalline MgB_2 prepared by high pressure synthesis. C(T) below 10 K vanishes exponentially, which unambiguously indicates a fully opened superconducting energy gap. However,…

We report a set of experimental data on local third-harmonic generation at microwave frequencies (0.5 GHz) in $YBa_2Cu_3O_7$ and Nb films. For local investigations of the nonlinear response a probe with inductive coupling was elaborated.…

Literature and experimental data about practical determination of phase composition and structure of BiHTSC ceramics from results of measurements of temperature dependence of magnetic susceptibility are presented. It is shown that Bi2223 to…

We report magnetic field dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the…

We discuss the temperature, frequency, and power-dependent surface resistance of the boride superconductor MgB2 in relation to possible applications for passive microwave devices. The data available in the literature are compared with…

Measurement of harmonic power on a suspended stripline microwave resonator patterned out of thin film YBa_2Cu_3O_7 (YBCO) has been carried out as a function of temperature and microwave power. The third harmonic power P_3 shows a subtle…

The lower critical field $H_{c1}$ has been carefully measured on a well shaped cylindrical sample of the new superconductor $MgB_2$ fabricated by high pressure synthesis. The penetration depth $\lambda$ is calculated from the $H_{c1}$ data.…

We present a magnetization study of low density YBCO ceramics carried out in magnetic fields 0.5 Oe < H < 50 kOe. It was demonstrated that superconducting links between grains may be completely suppressed either by a magnetic field of the…

We consider the far-infrared and the microwave conductivities of a two-band superconductor with non-magnetic impurities. The strong coupling expressions for the frequency and temperature dependent conductivity of a two-band superconductor…

We synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of…

MgB2 superconducting wires with critical temperature Tc approaching 40 K were used for preparation of MgB2/Ag and MgB2/In junctions. The differential conductance vs. voltage characteristics of N-S junctions exhibit clear contribution of…

We address the effect of MgO impurity on the superconducting properties of MgB2. The synthesis of MgB2 is very crucial because of sensitivity of Mg to oxidation which may lead to MgO as a secondary phase. Rietveld refinement was performed…