Relaxation of the normal electrical resistivity induced by high-pressure in strongly underdoped YBa2Cu3O7–δ single crystals

We investigate the relaxation of the normal electrical resistivity, induced by high-pressure in YBa₂Cu₃O_6.45 single crystals. It is determined that the pressure affects to the phase composition of the sample. Under pressure phases with different (but similar) critical temperatures form. It is determined that the application-removal pressure process is completely reversible. Above T_c the temperature dependence of the resistivity in the layers' plane at different hydrostatic pressures can be approximated with high accuracy with the scattering of electrons by phonons model. With increasing pressure, the residual resistance is reduced and the contribution of intraband s–s scattering increases. Additionally, the role of the interband s–d scattering and the Debye temperature is enhanced.     

Correlation between the mechanical and magneto-transport properties of cobalt film on semiconducting substrate

We have investigated the mechanical and magneto-transport properties of electron beam evaporated Co film on p-Si(1 0 0) substrate. Real time intrinsic stress measurement of the Co film, measured using a cantilever beam technique, shows the evolution of a large tensile stress with the growth of the film on the Si substrate. The analysis of stress reveals a columnar type Volmer–Weber growth which is also confirmed by the atomic force microscopy (AFM) measurements. The Co-film shows high positive (negative) magnetoresistance at all temperatures (below 10 K) on application of out-of-plane (in-plane) magnetic field.     

ITO/Au/ITO multilayer thin films for transparent conducting electrode applications

Transparent and conducting ITO/Au/ITO multilayered films were deposited without intentional substrate heating on polycarbonate (PC) substrate using a magnetron sputtering process. The thickness of ITO, Au and ITO metal films in the multilayered structure was constant at 50, 10 and 40 nm, respectively.Although the substrate temperature was kept constant at 70 °C, ITO/Au/ITO films were polycrystalline with an (1 1 0) X-ray diffraction peak, while single ITO films were amorphous. Surface roughness analysis indicated ITO films had a higher average roughness of 1.76 nm, than the ITO/Au/ITO film roughness of 0.51 nm. The optoelectrical properties of the ITO/Au/ITO films were dependent on the Au thin film, which affected the ITO film crystallinity. ITO/Au/ITO films on PC substrates were developed with a resistivity as low as 5.6 × 10⁻⁵ Ω cm and a high optical transmittance of 71.7%.     

Characteristics of Ni films deposited on SiO2/Si(1 0 0) and MgO(0 0 1) by direct current magnetron sputtering system with the oblique target

280 nm-thick Ni films were deposited on SiO₂/Si(1 0 0) and MgO(0 0 1) substrates at 300 K, 513 K and 663 K by a direct current magnetron sputtering system with the oblique target. The films deposited at 300 K mainly have a [1 1 0] crystalline orientation in the film growth direction. The [1 1 0]-orientation weakens and the [1 1 1]- and [1 0 0]-orientations enhance with increasing deposition temperature. The lattice constant of the Ni films is smaller than that of the Ni bulk, except for the film grown on MgO(0 0 1) at 663 K. Furthermore, as the deposition temperature increases, the lattice constant of the films grown on the SiO₂/Si(1 0 0) decreases whereas that of the films grown on the MgO(0 0 1) increases. The films deposited at 300 K and 513 K grow with columnar grains perpendicular to the substrate. For the films deposited at 663 K, however, the columnar grain structure is destroyed, i.e., an about 50 nm-thick layer consisting of granular grains is formed at the interface between the film and the substrate and then large grains grow on the layer. The Ni films deposited at 300 K consist of thin columnar grains and have many voids at the grain boundaries. The grains become thick and the voids decrease with increasing deposition temperature. The resistivity of the film decreases and the saturation magnetization increases with increasing deposition temperature.