Ni Layer (ni + layer)

Distribution by Scientific Domains


Selected Abstracts


Oscillations of the critical temperature in superconducting Nb/Ni bilayers

ANNALEN DER PHYSIK, Issue 1-2 2003
A.S. Sidorenko
Abstract We investigated Nb/Ni bilayers prepared by magnetron sputtering on glass subtrates. The quality of the films was characterized by small-angle X-ray diffraction analysis. The thickness of the layers was determined by the Rutherford backscattering spectrometry (RBS). For specimens with constant Nb layer thickness we observed distinct oscillations of the superconducting critical temperature upon increasing the thickness of the Ni layer. The results are interpreted in terms of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like inhomogeneous superconducting pairing in the ferromagnetic Ni Layer. [source]


Effects of uniaxial stress on the magnetic properties of thin films and GMR sensors prepared on polyimide substrates

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2008
Berkem Özkaya
Abstract The effects of externally applied uniaxial stress on the magnetic properties of Co thin films and pseudo-spin-valve (PSV) structures on flexible polyimide substrates were investigated. The advantage of the polyimide substrate is its flexibility and high elasticity (,1%), which cannot be achieved using conventional crystalline substrates. The Co layers exhibit a macroscopic easy axis induced by the preparation process. When the stress is applied perpendicular to the induced in-plane easy axis, the magnetic domains in the film rotate towards the applied stress direction, which was confirmed using Kerr microscopy and magneto-optical Kerr effect (MOKE) magnetometer measurements. A Co/Cu/Ni PSV system was prepared on polyimide substrate with dc magnetron sputtering. Applying uniaxial stress leads to opposite rotation of the magnetisation directions in both layers to each other due to different signs of the magnetostriction coefficients of Co and Ni. The magnetisation and giant magnetoresistance (GMR) curves under applied stress were recorded using in situ MOKE and current in-plane four-point probe techniques, respectively. When the stress is applied perpendicular to the external magnetic field (Hext), the operating range of the GMR sensor increases, whereas the sensitivity decreases. Anisotropy energies and saturation magnetostriction values of the Co and Ni layer were determined by fitting the GMR and magnetisation curves using a micromagnetic model. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Oscillations of the critical temperature in superconducting Nb/Ni bilayers

ANNALEN DER PHYSIK, Issue 1-2 2003
A.S. Sidorenko
Abstract We investigated Nb/Ni bilayers prepared by magnetron sputtering on glass subtrates. The quality of the films was characterized by small-angle X-ray diffraction analysis. The thickness of the layers was determined by the Rutherford backscattering spectrometry (RBS). For specimens with constant Nb layer thickness we observed distinct oscillations of the superconducting critical temperature upon increasing the thickness of the Ni layer. The results are interpreted in terms of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like inhomogeneous superconducting pairing in the ferromagnetic Ni Layer. [source]


Oxidation treatment on Ni/Au Ohmic contacts to p-type GaN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
Z. Z. Chen
Abstract Current,voltage (I,V) characteristics, transmission line method (TLM), and optical transmittance measurements are performed to investigate the effects of thermal oxidation and plasma-induced oxidation treatments on Ni/Au contacts to p-type GaN. Whether oxidation and thermal annealing are performed simultaneously or in succession, the specific contact resistances of Au/Ni/p-GaN are reduced. As to plasma-induced oxidation, neither no-oxidation nor long-time oxidation treatments on Ni/Au layers are suitable for obtaining a low-resistance Ohmic contact. The roles of oxidation are believed to activate the Mg acceptor in p-GaN and to form an oxygenous intermediate semiconductor layer, which may lower the Schottky barrier height between the metal layer and p-GaN. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]