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Related papers: Microwave performance of high-density bulk MgB2

200 papers

Employing a broadband microwave reflection configuration, we have measured the complex surface impedance, $Z_S(\omega,T,H)$, of single crystal La$_{0.8}$Sr$_{0.2}$MnO$_3$, as a function of frequency (0.045-45 GHz), temperature (250-325 K),…

Strongly Correlated Electrons · Physics 2007-05-23 Andrew Schwartz , Marc Scheffler , Steven M. Anlage

Printed circuit metasurfaces have attracted significant attention in the microwave community for their versatile wavefront manipulation capability. Despite their promising potential in telecommunications and radar applications, few…

Applied Physics · Physics 2021-04-08 Andreas E. Olk , Pierre E. M. Macchi , David A. Powell

We report measurements of the microwave surface impedance of the borocarbide family of superconductors LnNi2B2C (Ln=Y, Er, Tm, Ho). The experiments enable direct measurements of the superfluid density, and are particularly sensitive to the…

The microwave (MW) photoresistance has been measured on a high-mobility two-dimensional electron gas patterned with a shallow triangular antidot lattice, where both the MW-induced resistance oscillations (MIRO) and magnetoplasmon (MP)…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Z. Q. Yuan , C. L. Yang , R. R. Du , L. N. Pfeiffer , K. W. West

We perform broadband phase sensitive measurements of the reflection coefficient from 45 MHz up to 20 GHz employing a vector network analyzer with a 2.4 mm coaxial sensor which is terminated by the sample under test. While the material…

Materials Science · Physics 2008-05-12 Elvira Ritz , Martin Dressel

We report a non-contact method for conductivity and sheet resistance measurements of graphene samples using a high Q microwave dielectric resonator perturbation technique, with the aim of fast and accurate measurement of microwave…

Materials Science · Physics 2015-06-15 L Hao , J Gallop , S Goniszewski , A Gregory , O Shaforost , N Klein , R Yakimova

The critical current density (Jc) of hot isostatic pressed (HIPed) MgB2 wires, measured by d.c. transport and magnetization, is compared with that of similar wires annealed at ambient pressure. The HIPed wires have a higher Jc than the…

The superconductivities of samples prepared by several procedures were found to degrade under ambient environment. The degradation mechanism was studied by measuring the change of surface chemical composition of dense MgB2 pellets (prepared…

The field-induced variations of the microwave surface resistance are investigated in two different samples of powdered MgB2. The experimental results can be justified in the framework of the Coffey and Clem model with fluxons moving in the…

Superconductivity · Physics 2007-05-23 A. Agliolo Gallitto , S. Fricano , M. Li Vigni

We present a study of the electrodynamic response of MgB2 pellets and thin film samples exhibiting critical temperatures ranging between 26 and 38 K. We have performed accurate measurements of the surface impedance ZS =RS+iXS as a function…

The non-linear microwave surface impedance of patterned YBCO thin films, was measured using a suspended line resonator in the presence of a perpendicular DC magnetic field of magnitude comparable to that of the microwave field. Signature of…

supr-con · Physics 2016-11-18 Durga P. Choudhury , Balam A. Willemsen , John S. Derov , S. Sridhar

Two issues related to the microwave surface impedance Z_s of MgB_2 thin film are discussed in this Letter, both being significant for potential microwave applications. At first, a correlation between Zs and Alpha = Xi/l was found, where Xi…

We present a modified method of preparation of the new superconductor MgB$_2$. The polycrystalline samples were characterized using x-ray and magnetic measurements. The surface barriers control the isothermal magnetization loops in powder…

Superconductivity · Physics 2007-05-23 M. Pissas , E. Moraitakis , D. Stamopoulos , G. Papavassiliou , V. Psycharis , S. Koutandos

There has long been a discrepancy between microwave conductivity measurements in high temperature superconductors and the conductivity spectrum expected in the simplest models for impurity scattering in a d-wave superconductor. Here we…

High-density bulk materials of a newly discovered 40K intermetallic MgB2 superconductor were prepared by high pressure sintering. Superconducting transition with the onset temperature of 39K was confirmed by both magnetic and resistive…

Superconductivity · Physics 2009-11-07 Y. Takano , H. Takeya , H. Fujii , H. Kumakura , T. Hatano , K. Togano , H. Kito , H. Ihara

Striking features have been found in the nonlinear microwave (8 GHz) surface impedance $Z_s=R_s + jX_s$ of high-quality YBaCuO thin films with comparable low power characteristics [$R_{res}\sim 35--60 \mu\Omega$ and $\lambda_L(15 K)\sim…

Superconductivity · Physics 2009-10-31 A. P. Kharel , Anton V. Velichko , J. R. Powell , A. Porch , M. J. Lancaster , R. G. Humphreys

The high-pressure synthesis is one of the most promising methods to produce MgB2 superconductive (SC) material. The available high-pressure apparatuses have working volume up to 100 cm3 which allows samples up to 60 mm in diameter to be…

We demonstrate that a near-field microwave microscope based on a transmission line resonator allows imaging in a substantially wide range of frequencies, so that the microscope properties approach those of a spatially-resolved impedance…

Materials Science · Physics 2007-05-23 Alexander Tselev , Steven M. Anlage , Zhengkun Ma , John Melngailis

The quasi-optical modulation of linear polarization at millimeter and sub-millimeter wavelengths can be achieved by using rotating half wave plates (HWPs) in front of polarization sensitive detectors. Large operational bandwidths are…

Instrumentation and Methods for Astrophysics · Physics 2016-10-04 Giampaolo Pisano , Bruno Maffei , Peter A. R. Ade , Paolo de Bernardis , Peter De Maagt , Brian Ellison , Manju Henry , Ming Wah Ng , Brian Schortt , Carole Tucker

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…

Superconductivity · Physics 2007-05-23 A. Agliolo Gallitto , G. Bonsignore , G. Giunchi , M. Li Vigni