Synthesis and physical properties of YBa2Cu3O7 single crystals
Аннотация
The growth of YBa2Cu3O7 single crystals at the surface of the melt under gradient conditions is described. The properties of the single crystals are studied extensively in normal and superconducting states. Experimental results suggest that a martensite-type transition occurs in the temperature region of 200–230 K. It is shown that the elastic properties and the coefficient of thermal expansion of the ceramic samples are controlled by the thermal activation processes. The fluctuation contribution to the electrical conductivity and the magnetic susceptibility is estimated from the temperature dependence of the electrical resistivity and the magnetic susceptibility anisotropy of the single crystals.