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Field evolution of vortex lattice inLuNi2B2Cseen by decoration in fields up to 1.5 kOe

“…It is to be noted that λ estimated by measuring the "vortex diameter" d in decoration experiments is in a fair agreement with other data also for YBCO, 19,20 for which an empiric relation d = 4λ yields λ 0 ≈ 150 nm and for NbSe 2 for which the procedure gives ≈ 270 nm.…”

Microwave response of single crystal YBa2Cu3O7−δ films as a probe for pairing symmetry

“…In the framework of a phenomenological approach in general the surface impedance of any superconductor can be described as (see, e.g., the review papers [3,18]):…”

“…[23] (2), (3) and the surface impedance (1), is the relaxation time t(T) of normal carriers. Basing on the phenomenological analysis of numerous experimental data on R s (T) of HTS single crystals [3][4][5][6][7][19][20][21][22] and thin films [17,18,23], it was shown that the most appropriate temperature dependence t(T) has the form:…”

“…In particular, the temperature dependence R s (T) in YBa 2 Cu 3 O 7-d (YBCO) perfect single crystals [1,[3][4][5]7,8] and epitaxially grown single-crystalline thin films [2,6,17] experimentally observed by different groups, turned out to be nonmonotonous and revealed a pronounced peak at T £ T c /2. The temperature position and the height of the peak depend upon the frequency and crystal perfection.…”

“…Numerous experimental and theoretical studies of microwave response, carried out during the last decade, revealed a lot of interesting features of the superconducting state in HTS metal-oxide compounds and partly shed light on the nature of superconductivity in these materials. For instance, the d-wave scenario of electron pairing symmetry in HTS is strongly supported by the data of microwave measurements [1][2][3][4][5][6][7][8][9]. However, all the features of the microwave response of HTS are not clear enough at present.…”