The reliability of fundamental studies of superconductivity depends on the quality of the materials under study. Optical zone melting yields high-quality single crystals without impurities, which can be difficult for other technologies. The paper describes the growth procedure for single crystals of several families of superconductors: bismuth high-temperature superconductors Bi2Sr2CaCu2O8 + δ and Bi2Sr2–xLaxCuO6 + δ and a superconductor with an assumed p symmetry of the superconducting order parameter Sr2RuO4. We discuss the search criteria for synthesizing high-temperature yttrium superconductors YBa2Cu3O7 + δ by optical zone melting, which do not lead to the formation of single crystals. The procedure for obtaining single crystals includes several stages. The first is to anneal a mixture of powders of the required oxides and carbonates, taken in specific proportions, at temperatures up to 850°C. A solid-phase reaction takes place, resulting in the desired polycrystalline complex oxide; rods with a length of ~5–10 cm are obtained from this oxide using a hydraulic press. The second stage is annealing of the rods in air at temperatures up to 940°C and, if necessary, melting in an optical-zone-melting unit using lamps with a rated power of 500 W at an adjustable power from 20 to 95% with a drawing speed of 20–30 mm/h. The third stage is the growth of a single crystal at 20–95% power at a rate of 0.1–20 mm/h. The result is a mixture that disintegrates upon cracking into single crystals up to several millimeters in size. Measurements of the temperature dependence of the dynamic magnetic susceptibility of the synthesized single crystals at a frequency of 100 kHz are carried out, which makes it possible to determine the temperature of the superconducting transition and its width.

The proposed technology of wet etching provides obtaining of stand-alone Bi2Sr2CaCu2O8 mesa structures thicker than ones usually being studied, but still allows to get mesas below 1 μm. The time required for the fabrication is much shorter than the standard method of ion milling. The development of technology is aimed to increasing of the copper plating up to 30 microns thick over a thin gold layer to improve heat removal. The measurements of fabricated samples over a wide temperature range from 6 to 77 K were performed. Also experimental study of spectrometer with the oscillator based on the BSCCO mesa structure obtained on the basis of standard ion milling technology was performed. In particular the BSCCO generator can be used to develop compact THz spectrometer with high resolution.

The technology of wet etching allowing fabrication of stand-alone BSCCO mesa structures was proposed. The produced mesas can be made much thicker than ones usually being studied. The time required for the fabrication is much smaller in comparison with the standard method of ion milling. The process used is controllable which provides acceptable precision of mesa fabrication. The IV characteristics of the sample showing Josephson nature were obtained. The qualitative comparison with characteristics of similar structures fabricated by other groups was carried out.

The vortex structure of Bi2Sr1.65La0.35CuO6+δ single crystals in tilted magnetic fields has been studied by the decoration method. From the observed pattern of vortex chains in the basal plane, the parameter of anisotropy in the superconducting state has been estimated as γS = 460 ± 40. The electric resistance of Bi2Sr1.65La0.35CuO6+δ single crystals has been studied in a broad range of temperatures (T c < T < 300 K) and magnetic fields (up to 16 T). The ratio of resistivities in the direction perpendicular to the basal plane and in plane near the critical temperature T c amounted to ρ⊥/ρ‖ = 3.2 × 105. A possible relationship between the anisotropy in the normal and superconducting states is discussed.