We report on the microwave surface resistance of two polycrystalline Mg<Superscript>11</Superscript> B<Subscript>2</Subscript> 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...</subscript></superscript>

We consider a superconducting material that exists in the liquid state, more precisely, in which the Meissner-Ochsenfeld effect persists in the liquid state. First, we investigate how the shape of such a hypothetical Meissner liquid will adapt to accomodate for an applied external field. In...

Strongly underdoped RuSr<Subscript>1.9</Subscript>La<Subscript>0.1</Subscript>GdCu<Subscript>2 </Subscript>O<Subscript>8</Subscript> has been comprehensively studied by dc magnetization, microwave measurements, magnetoresistivity and Hall resistivity in fields up to 9 T and temperatures down to 1.75 K. Electron doping by La reduces the hole concentration in the CuO<Subscript>2</Subscript> planes and...</subscript></subscript></subscript></subscript></subscript>

We discuss the microwave energy losses in superconductors in the critical state. The field-induced variations of the surface resistance are determined, in the framework of the Coffey and Clem model, by taking into account the distribution of the vortex magnetic field inside the sample. It is...

We discuss the microwave second-harmonic generation in high-density bulk MgB<Subscript>2</Subscript>, prepared by the reactive liquid Mg infiltration technology. The intensity of the harmonic signal has been investigated as a function of temperature and amplitudes of the DC and microwave magnetic fields. The results...</subscript>

We discuss the hysteretic behavior of the field-induced variations of the microwave surface resistance in superconductors in the critical state. Measurements have been performed in a bulk sample of Nb and a powdered one at different values of the temperature. We discuss a model, based on the...

We present ac susceptibility measurements performed on (K, Ba)BiO<Subscript>3</Subscript>single crystals with different geometries: thick films, bars and hollow cylinders. We show that the h <Subscript>ac</Subscript> dependence of the real (χ′) and imaginary (χ′) parts of the ac susceptibility is in very good agreement with Brandt’s...</subscript></subscript>