Resistivity and Hall effect in sputtered Nb/Ni multilayers

Journal Article · Tue Nov 15 00:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.9503· OSTI ID:7017007

Perez-Frias, M T; Vicent, J L

Multilayered samples of Nb/Ni have been fabricated by dc triode sputtering. X-ray diffraction patterns were obtained in the reflection geometry. Small-angle data show several order peaks and subsidiary maxima, indicating strong composition modulation. ..omega..-rocking curves at small angle are sharp, with ..delta omega..approx.0.1/sup 0/. High-angle scans do not show superlattice peaks. The samples have (110) texture for Nb and (111) texture for Ni. Multilayered systems with severe structural size mismatch are incoherent, and Nb/Ni multilayers are among these incoherent systems. Resistivity measurements show logarithmic minima at low temperature. These minima depend on bilayer thickness, shifting, and deepening to a higher temperature with decreasing modulation wavelength. Their origin could be due to weak localization. We have explored the contribution of Ni and Nb layers to this resistivity effect. The role of Ni layers is unclear at present, but we can rule out a modified Kondo mechanism. However, the short mean free path of the conduction electrons in Nb layers, estimated from Gurvitch's model, could play a clear role in this weakly localized regime. The Hall effect in Nb/Ni multilayers shows a clear ferromagnetic character with very well-defined ordinary, R/sub 0/, and extraordinary, R/sub s/, coefficients. The samples have saturation magnetizations and hysteresis loops down to nominal 10-A layer thickness of Ni. The Hall-effect data could be a hint of dimensional effects in ferromagnetism. R/sub 0/ and R/sub s/ are temperature independent between 4.2 and 100 K. R/sub 0/ is also bilayer-thickness independent, and the carrier concentration seems to remain constant for a fixed Nb/Ni layer thickness ratio.

• Research Organization: Departamento Fisica de Materiales, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid, Spain
• OSTI ID: 7017007
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Vol. 38:14
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NICKEL
ELECTRIC CONDUCTIVITY
HALL EFFECT
NIOBIUM
ELECTRONS
FERROMAGNETISM
HYSTERESIS
LOW TEMPERATURE
MEAN FREE PATH
MEDIUM TEMPERATURE
SPUTTERING
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE
X-RAY DIFFRACTION
COHERENT SCATTERING
DIFFRACTION
ELECTRICAL PROPERTIES
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
MAGNETISM
METALS
PHYSICAL PROPERTIES
SCATTERING
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties