Fluxon dynamics by microwave surface resistance measurements in MgB2
نویسندگان
چکیده
منابع مشابه
Fluxon dynamics in Li-Al codoped MgB2 by microwave surface resistance measurements
The magnetic-field-induced variations of the microwave surface resistance, Rs, have been investigated in ceramic Mg1−x(LiAl)xB2, with x in the range 0.1 ÷ 0.4. The measurements have been performed on increasing and decreasing the DC magnetic field, H0, at fixed temperatures. At low temperatures, we have observed a magnetic hysteresis in the Rs(H0) curves in all the investigated samples. On incr...
متن کاملFluxon dynamics by microwave surface resistance measurements in MgB 2
Field-induced variations of the microwave surface resistance, Rs(H), have been investigated in high-density ceramic MgB2. At low temperatures, several peculiarities of the Rs(H) curves cannot be justified in the framework of models reported in the literature. We suggest that they are ascribable to the unconventional vortex structure in MgB2, related to the presence of two gaps. On the contrary,...
متن کاملEnergy gap, penetration depth, and surface resistance of MgB2 thin films determined by microwave resonator measurements
We have measured the temperature dependence of the microwave surface impedance Zs5Rs1ivm0l of two c-axis oriented MgB2 films employing dielectric resonator techniques. The temperature dependence of the magnetic-field penetration depth l determined by a sapphire dielectric resonator at 17.9 GHz can be well fitted from 5 K close to Tc by the standard BCS integral expression assuming the reduced e...
متن کاملThe superconducting gap of in situ MgB2 thin films by microwave surface impedance measurements
Precision measurements of the microwave surface resistance Rs of in situ MgB2 films directly reveal an exponential behavior of Rs at low temperature indicating a fully-gapped order parameter. The entire temperature dependence of Rs is well described by a Mattis–Bardeen formalism, but with a small gap ratio of D(0)/kTc50.72, corresponding to D(0)51.9 meV. © 2002 American Institute of Physics. @D...
متن کاملMicrowave surface resistance of pristine and neutron-irradiated MgB2 samples in magnetic field
We report on the microwave surface resistance of two polycrystalline Mg11B2 samples; one consists of pristine material, the other has been irradiated at very high neutron fluence. It has already been reported that in the strongly irradiated sample the two gaps merge into a single value. The mw surface resistance has been measured in the linear regime as a function of the temperature and the DC ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physica C: Superconductivity
سال: 2004
ISSN: 0921-4534
DOI: 10.1016/j.physc.2003.09.103