Hall effect in amorphous thin-film magnetic alloys

Journal Article · Fri Jul 01 04:00:00 EDT 1977 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.324111· OSTI ID:7099058

McGuire, T R; Gambino, R J; Taylor, R C

Amorphous magnetic alloys have unusually large extraordinary Hall coefficients (R/sub s/) defined by the ratio of the Hall resistivity to the net magnetic moment of the alloy. We have studied the Hall effect in amorphous films in the ternary ferrimagnetic systems Co-Gd-Mo and Co-Gd-Au, alloys which exhibit compensation temperatures (T/sub comp/). Above T/sub comp/ the Hall coefficient R/sub s/ is positive and below T/sub comp/ the sign of R/sub s/ changes to negative in a discontinuous manner, probably limited by the homogeneity of the sample. We have also prepared amorphous Gd-Au and Y-Co films and measured R/sub s/ which we use to qualitatively separate the effects of the Co and Gd sublattices in the ternary alloys. We attribute the sign of R/sub s/ to a combined effect of a negative Gd and a positive Co Hall coefficient. Above T/sub comp/ the Co is dominant and points in the direction of the applied field H while Gd is antiparallel to H. Thus, both sublattices contribute in a positive sense to R/sub s/. Below T/sub comp/ the Gd moment is dominant and the sign of R/sub s/ is reversed for both sublattices. Values of R/sub s/ up to 25 x 10/sup -9/ ..cap omega.. cm/G are measured near T/sub comp/ and when Mo is present R/sub s/ is reduced to 5 x 10/sup -9/ ..cap omega.. cm/G. Molybdenum is known to cause a strong decrease in the moment of the cobalt sublattice and this probably is the reason R/sub s/ decreases. Our interpretation of the Hall effect in these ferrimagnetic systems differs from other recently proposed models.

• Research Organization: IBM T.J. Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 7099058
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 48:7; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
AMORPHOUS STATE
COBALT ALLOYS
COBALT BASE ALLOYS
FERRIMAGNETISM
FILMS
GADOLINIUM ALLOYS
GADOLINIUM BASE ALLOYS
GOLD ALLOYS
GOLD BASE ALLOYS
HALL EFFECT
IRON ALLOYS
IRON BASE ALLOYS
MAGNETIC MOMENTS
MAGNETISM
MOLYBDENUM ALLOYS
RARE EARTH ALLOYS
YTTRIUM ALLOYS