H. Wang et al., Magnetic domain structures and giant magnetoresistance of granular (Ni74Fe16Co10)(35)Ag-65 films, J APPL PHYS, 88(7), 2000, pp. 4216-4220
In this article, granular (NiFeCo)(35)Ag-65 films having a nominal atomic r
atio of Ni:Fe:Co = 74:16:10, near the zero magnetostriction ternary alloy,
were prepared by dc magnetron co-sputtering. Subsequent thermal annealing w
as performed in a vacuum (< 2 x 10(-3) Pa) furnace for 1 h at various tempe
ratures ranging from 250 to 500 degrees C. The crystalline structure and ma
gnetic structure of the as-deposited and annealed films were characterized
by Rutherford backscattering spectroscopy, x-ray diffraction, atomic force
microscopy, and magnetic force microscopy. The giant magnetoresistance (GMR
) for the films was measured as a function of temperature between 20 and 30
0 K using a conventional four-point probe dc technique in the presence of a
magnetic field up to 7.6 kOe. It was found that, the crystalline structure
, the magnetic structure, and consequently the GMR were closely related to
the thermal treatment. The film annealed at the temperature of 300 degrees
C has the isolated single domain structure and the highest GMR value of 19.
1% at 20 K, while the film annealed at 500 degrees C has the long-range dom
ain structure and the lowest GMR value of 9.9% at 20 K. (C) 2000 American I
nstitute of Physics. [S0021-8979(00)04920-3].